It does what it does, and absolutely works in moderation. If you want an extra bass knob and program-dependent brightness it can do it, but it can easily be too much. I think it was Steve Lukather who once said it´s like cocaine for your tone, and that´s coming from a dude that knows a thing or two about cocaine.
With that said it seems to work better with recorded tones or after a speaker emulation, sticking one in a FX loop or after a preamp doesn´t play as nice. That extreme harmonic treble content you have in a distorted guitar signal before the speakers round it off makes the BBE do weird things sometimes, since it tries to balance the treble to the mid range in some predetermined fashion. I think they stopped talking about it for later versions, but it can actually reduce treble if there´s too much already.
Whether the sales lingo of phase alignment and micro delays actually do anything, well, that´s up for debate. And the sucky bypass is sometimes said to be a feature, not a bug, so having it in a bypass loop is a given unless you want it on all the time.
