Is anyone out there Biamping their Proacs?

Biker, the D15 is just a small two-way where biamping is really unnecessary. The upper amplifier would just be driving the tweeters. Get ONE higher quality tube amplifier with 50 watts or more and biwire.

The only way to even have a chance at decent, coherent, sound when biamping a two-way where the crossover is in the critical human hearing range would be with identical amplifiers. But why bother? It's not only a waste with this speaker, but is more likely to do harm than good.

excellent info- sounds like sticking with one real nice tube setup will be the way to go.

Regarding the Proac match with tube amps, that's not necessarily true.
Stuart Tyler, the owner of Proac, uses Sugden Masterclass series to listen to his speakers at the Proac Factory. I'd buy a pre-owned Sugden Masterclass int-amp( around $3,5k) and be done with it.
Sugden is one of the few brands you never hear about, because they refuse to spend dough on kitschy advertizing.