Boss is not even in the same league as TC Electronics. That's closer to Evantide quality.

The G-System is awesome. As a complete system, I don't know of anything that really compares. Maybe the new Fractal Audio effects only thing is in the same league. I've been using one for about five years, I think. Yes, you can do amp switching with the G-System, yes, you can and should use the 4-cable method to unleash its powers. Moreover, there's bunch of loops that you can switch on and off where you can put your pedals. I have my preamp in one of the loops, so I can put the wah and comp before it.

I haven't tried the new Boss GTs but I had the Boss GT Pro and the G-System is much, much better.

OTOH if you want the Boss sound their pedals make
TC isn't gonna give it to you

So I'm looking over the G system and one thing I'm not seeing is amp control. Can the G system change your amps channels? If it can't this thing is stupid. How could you build a patch and not have the ability to change you're amps channels?
So if I want a clean tone with Delay in the effects loop and then want to change to the Drive channel with another delay setting and maybe a OD pedal in front of the amp , how can this get done on a Preset if the G system can't change your amps channels?

What am I missing here?

Yes it can...either MIDI or stereo cables...depends what your amp has. There's info online...

It can do switching via MIDI or relays:

http://www.tcelectronic.com/g-system/

if you want the sound of a particular Boss pedal, you can throw that pedal in one of the loops in the G-System

Look at pictures of its back. It has two stereo relays. They're called SW OUT.

Here is exactly what I do.

1) Clean channel of my amp with Chorus , Delay and sometimes Reverb in the Loop of my amp. Out in front of my clean channel I will have OD pedals of some kind depending on what I'm doing or not. The Boss Routes all this exactly how you want.
So example would be,
Guitar- OD-My amps preamp-chorus-my amps amp. In this chain the Boss is the provider of all effects and routing. It also has a tuner and volume pedal in lets call this patch 1.
With the 4 cable method you wire you rig like this.
Guitar into the GT100 Input
Send goes to the front of your amps preamp section or guitar input on the front
Return goes to the Send of your effects loop
Output goes to the return of your guitars effects loop.
This is a very powerful wiring as placing effects can go exactly where you want them to be or IMO where they should be. Modulation effects don't sound as good to me in front of the amp especially when you want to use the drive channel of your amp as well. If you had just a clean channel only like a Fender Twin then everything can live out front and you can get wonder tones which will now greatly rely on your effects chains order or pedal order if you will.

So with the G system I would want to re create this very same thing but the G system needs external devices to do the same exact thing.
So IF I want a volume pedal, I have to add it to the chain of the G system out in between the out and the return of my amps effects loop.
If I want OD pedals of any kind, I gotta put then in-between the Guitar and the input of the G system or in one of their Loops IF it can place that effect in front of my amps preamp. how could you BOOST your drive channel or get a nice OD tone in front of your clean channel if it couldn't?
IF the G system can have a OD pedal in it's loop and I can make a patch where the Pedal just stays on all the time and I can have it routed exactly how I want it, it makes this Processor more desirable.
So really the only things it's missing as far as what I would want to use is
1) Volume pedal or Wah
2) OD or distortion pedals
It looks to have everything else inside with Chorus , delay , reverb built in. I really don't care about other effects maybe a Octa Pedal. I don't really use anything else.

I think I'm gonna order one from Sam ash and take advantage of the return policy IF I hate it or it doesn't outperform the GT100 by a lot because getting the G system to where the Boss GT100 is It's gonna be a bit over $1000 + due to the additions of external pedals and more wiring. But if it does sound better , who cares if it costs 2x's or more the price?

Honestly I wish Boss would just build a effects Processor that can be rack mountable and controllable with a external floor board. Remove all the stupid Cosmo amp crap and just be a straight effects processor and switching control unit. I think the quality can be the best they can build and I would pay $999.99 or more for it. The GT100 at retail is $599 which IMO is a complete bargain especially for what you can do with it. It's fully impressive BUT the only thing I don't like is the fact I feel I lose about 5-10% of my amps tone. It gives it this slight Processed sound I can't seem to dial out. I want the GT100 or a new model to sound EXACTLY like if I had all pedals but with the ability to control everything volume pedal Wah and tuner all built in. The GT100 is 90-95% there now and I bet most Guitar players who own it love the hell out of it. But I'm a tone freak and want my tone to be the best it can be with my tuning. It's why I'll go back to pedals sometimes just to get the very best sound out of my rig. I play my best and write my best when my tone is ON. When it's altered I'm annoyed and it messes with me sometimes to the point I don't want to play anymore.

Yeah I have issues people make no mistake. But I'm sure most of you feel as I do or you wouldn't be hanging around in this forum LOL

Last time I checked, the TC is just effects, and doesn't have any preamps or speaker modelling. It was/is also more expensive than the GT-100. Boss did once do a GT Pro, which was the rackmount version of the GT-8. I'd love to have rackmount versions of the GT-10 and GT-100, but it just isn't going to happen. I also own an Eventide Eclipse, and I don't think anything I've heard from TC (have tried a G-System and used to own a FireworX, a D-Two and a Voiceprism) will sound even close to an Eventide. That said, I would only use my Eclipse for special FX, and definitely NOT for guitar/amp modelling.

Mantis, you can do all that with the G-System. The loops are placed before all the effects you would typically put in the effects loop of an amp but after the comp and filter (e.g., wah). You can run something in front of that, of course, if you want. You put the preamp of your amp in the insert loop, which is the last of the loops. That way, you can use your OD or whatever to boost the signal before the preamp. You could even run different preamps in different loops.

The Eventide stuff is a different story altogether, by all accounts, but I don't think they even offer a system like the G-System.

I'm gonna bring one home and test drive it. I'm all about tone but I'm also about control. I don't like giving one up for the other. They are both equally important to me especially for how I like my rig to work.
I really want Bose to make a Waza Craft Level GT100 and remove the Amp modeling crap. I don't use any of that stuff as I don't like fake sounding amp modelers. I never heard a amp modeler that sounded and felt like the real thing. I don't play all kinds of different music anyway so for me there is no need to have 30 different amps or more on stand by.
That is why I love the GT100 so much as I get exactly what I need out of it as I turn off all the other crap it has and use whats useful to me. But IF Bose could make an even better higher quality more organic analog pure sounding unit, I would be in heaven. I wrote them a very detailed letter about the Waza Craft ideal , pricing and what nots.
Think about this for a minute, if you could have a Bose unit that sounds exactly as stand alone pedals with all it's ability to build patches and call upon them at will with just one foot press wouldn't you pay more then the asking price of this unit now? It's going for now $499 pretty much everywhere and when I purchased it , it was $599. I would be fully willing to pay lets say $999- $1999 easy. Think about how much you have to invest in 5 or 6 pedals, cables , pedal board , power center , cables and then you gotta manage all of that.
This G system is very attractive but I see many negatives with it not having all effects and a expression pedal on board for volume , wah or both.