I'm simply uncertain why anyone actually NEEDS a big old CMP on the final output.
Yamaha's, on the whole, are not exactly brimming with heart stopping dynamics, the drumkits sound pretty squashed already. And now you are going to strap a compressor across the whole thing as well?
WHY...?
Doesn't it sound great without one?
Correct me if I'm wrong, but doesn't the T3 have just the one main CMP across the main outs? Or, like the E80, does it have TWO? One across the Style and SMF section, and one across the played Keyboard Parts.
I feel, if you are going to use any compression at all, this is way preferable, as an enthusiastic or overly loud keyboard part (we all tend to play a little louder than most tracks really need) is going to 'duck' the accompaniment tracks, and make a mess of the balance between played and arranged parts.
Without this, I feel that the best course of action is to simply avoid the CMP altogether, and simply work the styles and SMF's so they don't NEED compressing!
BTW, just a little OT...
If any of you DO want to put a little 'squeeze' on their sound, without as many compression artifacts as the built-ins do, I heavily recommend the little FMR RNC compressor, from FMR Audio. Less that $200 (better than most ten times the price), quality construction, and in 'SuperNice' mode, on of the most transparent mix bus comps I have ever had the pleasure to use.
Put it on the main outs of your PA, dial in just a few db of gain reduction, and stand back! You won't hear it working, but your overs are gone, your PA's headroom increased, all without it screwing up your mix...
It's a gem.