I've been wrestling with boosts for my ED, and I think I have a good thing going now.
First off, I should say that one thing I really like to avoid is using my effects loop. I know, I know... it just adds another setup step and if I'm going to be hauling this amp around, I want to keep everything else as minimal as possible and just run everything straight in, if I can. That unfortunately eliminates my option to put a clean boost in the loop, which is the best and cleanest way to get a volume bump for solos... and I tried that for a while, but argh for such a TINY boost in volume (all we need is a little bit, right?) it just didn't seem worth the extra cable hookup.
But that's just me. Anyway, here's what I am using and I like what I have going right now.
For juicing the front for a little more sustain: Xotic EP Booster.
As a solo boost: Barber Compact Direct Drive.
I was surprised at how effective the CDD is as a solo boost. I'd tried the BB Preamp, Gain Changer, v3 OCD, Fulldrive 2, KOT, POT, Amp11, and a few others. Great pedals, but none of them really helped make my solos more audible in the mix. I run the CDD in Fat/Hi modes, output at 2:00 and gain at 9:00, tone at 12. It gives me *just enough* of the right sort of boost to get over the top.