Powders offer more bang for your buck. Would you rather swallow 15 capsules per serving, or have to take a powder in one glass of 10oz of h2o?
I use TrueProtein BCAAs, mixed with EAA's. The flavoring (I do recommend flavoring with ANY BCAA product, unless you're a masochist!), I usually use watermelon, though I'm going to try the Kool-Aid flavor next as I'm hearing good things about that.
I've used ON's BCAAs too, but wasn't impressed...I just kind of like the idea of ordering X amount of powder, and unless something has changed, ON didn't allow you to do this- it was a choice of two smaller bottles that I would have to purchase 2 every few weeks....