Hahaha....shhh, we were never supposed to tell we used those crappy Behringer's! LOL!! I actually never used them for sims, but lightly on just about everything else. I have no idea why those junkers did so well with conditioning signals to disc. For sims, my best weapons were my Drawmer Tube compressor, a Manley ELOP and then the pedals like the TS808, or some over-drive, or the blue Boss Compressor Sustainer was the best. That's the problem with amp sims...they lack the buffered signal push like the front end of a real amp has.
So when you drive it a little bit, it can make a world of difference. When I worked for Acme Bar Gig and was developing Shred and Headcase plugins, we did lots of work on the front end of our plugs. We had a few things no one else had at the time that really made an awesome difference in the way the sim behaved. The down side was, it just never sounded or reacted like a tube amp. The up side was, it sounded great as far as transistor sounds go and it also had sustain.
That's the huge fault with amp sims and plugs. They give you balls full of distortion, but the sustain just isn't there unless you jack your monitors to the point of feedback. This is where a stomp box going first can really help. Take like an over drive or the Boss comp/sustainer or a tube screamer, run the output level all the way up, drive all the way down, and mess around with the one up the middle. If you have a little hiss, back the output down a bit. You shouldn't need any drive from the TS.
We've come a long way with amp sims and the like. I have an endorsement with Fractal Audio at the moment and also do quite a bit of beta testing and help with development. Now THAT is an off the hook, sophisticated system! The amps in that are the real deal and the possibilities are limitless. Yeah it's pricey as heck, but it's the last pre-amp I'll probably ever get. I've since sold all my amps because I really don't need them. Between the AX8, FX8, AxeFxII and the XL+, I'm in heaven over here! The best stuff I've ever played through hands down. Anyone in or near NJ, come try them out!
The other thing about amp sims....is copping the 12AX7 front end. I've not heard many people do this and make it convincing. You can always hear it when you back down a volume or in pinch harmonics. It gives it right away for me. Transistor stuff just sounds weird with backed down volume and the transients don't clip off as smooth or as warm.
And lastly, cab IR's are huge for getting great tones with sims. There are companies putting them out now that are truly amazing. High passing and low passing on cab IR's is super important too as you can remove that sub low push and sizzle that shouldn't be in a guitar tone any way. The other thing that can really help is pre-eq...before the tone stack or plugin. Eq-ing your signal before it hits the plug with a little dirt pushing the eq level a bit can be huge in tone sculpting. That was one of the cool things about Rocktron stuff...they always gave you pre and post eq. I never thought their stuff sounded tubey enough, but I always got great results due to the pre eq. Good stuff.
Pedals probably won't be the same Brian. Then again, it depends on which ones as well as what they are capable of. Some of those boutique pedals sounds pretty cool on their own, but still need an amp to really come to life. Driving things in front of them sometimes skewers the sound. A little compression will never hurt though.