For leads, I'm going to be using the 4th channel on my Mod50.
But if you're talking about boosts and stuff, Matt has had great luck with the BB Preamp. That pedal is like the best sounding tubescreamer ever. Active bass and treble controls are GREAT.
I love using
my Xotic RC Booster. Its very clean. Whereas the BB is like a really, really great sounding tube screamer pedal, and definitely has that op-amp flavored overdrive flavor, the RC is a full frequency clean boost that can add *some* grit. But it's not like BB, tubescreamer grit. It's like crank a fender twin to 6-7 grit. Very subtle yet tubey and oganic, but glassy and big. You know how when you crank a clean channel on a Fender up, and it's not necessarily breaking up, but you can hear some tube compression going on, and it just starts to sound bigger and react differently? That's what the RC simulates to my ears.
Amp set to dead clean, Stepping on the BB, you're like "OK, i turned on a pedal/switched channels"
Amp set to dead clean, Stepping on the RC, you're like "OK, sounds like I turned my amps clean channel up, but I really didn't"
Two different beasts.
For my backup, small gig rig, I'm using
a MI Audio Crunchbox > RC Boost >
Fender Blues Deluxe. Having the boost AFTER the distortion pedal allows me to have more volume, as well as gain and compression, for leads.
PS: Matthew, I am not hating on your BB at all. Great Pedal. I'll take that over a tubescreamer anyday.