After a nice Lead sound

Maybe letting the guys know what Guitar type your using might help

Try my Legacy's

Steve uses a Rack compressor/sustainer in his backline. try adding a little of that in the stomps, and try blending that with the amps compression setting also.. you can get a nice sustain that way..

AFAIK Steve Vai uses a tube screamer in front of his amp, 1/3 of the gain comes from that. I'd try dialing a tube screamer with the following settings: gain 1.5, tone -1.2, volume 0.5. Of course for that to work well with your profile it needs to have amp gain around 5.0-7.0.

Then you need to add mids (usually up to 0.5 will do) and shave off some presence (-0.1 to -0.3) and lows (up to -2.0) if it's too boomy. And increase definition a little if the profile allows for it (you'll know, if it doesn't it will start to sound unpleasantly ice picky). Then experiment with the clean sens control, your guitar is probably fairly high output, I have one with a PAF Pro that I need to set clean sens to 0.5 with it. Setting the sweet spot of the profile should go as follows: too low and it will sound too bright, too high and it will sound too bright also. There will be a range in between those clean sens settings that will sound a bit muffled in comparison, you'll want to set the clean sense control right in the upper transition from muffled to bright. Does that make any sense? I've dialed some pretty nice lead sounds this way.