I just recently updated my Spider IV 150 to current specs and am exploring the new Gain effects.
One thing that has always bothered me with modeling amps is the slight delay when switching amp models or channels (from A to B etc.)
It occurred to me that with the new Gain effects, you don't have to switch channels to switch to your dirty sound. It's almost like the difference between switching channels and stepping on a distortion pedal (which I assume is what Line 6 was going for). My only issue is that the Gain stomps just don't quite have the same feeling as the amp models with drive cranked up. I've found that Tube Driver gets pretty close for a good rock to metal sounds, when compared to the cranked Class A Red or Insane Red. The Screamer is nice too but, I don't know how to describe it...
I suppose what I kept running into is two conflicting EQs between the amp model and the stomp model (which just took time to find a good balance or just pick a new FX1 option) and a difference in output level, the cleans always seem to be more full and a little louder then when I kick in the Stomp effect.
In the end I guess what I'm asking is if other people run into this to, how they deal with it, how they use the Gain effects, if anybody has some tips how to apply those effects along with channel volume, gain, drive etc. and lastly do people prefer to switch from A to B for clean/dirty or use the effects?