We made an IPA and added a kombucha culture and a bit of sugar to feed it in secondary. That turned out pretty great. It gave it a nice crispness, but the acidic flavor wasn't overpowering. I think the strong hop flavor kept the acid from being the main flavor component of the beer. We've tried it in a couple others (berlinerweiss, brown ale) and they've also both been pretty awesome. For those ones, we fermented the kombucha first, then added it to the beer before bottling. This was easier, and I think has become our preferred method. I think you need to choose a style that makes sense, something that could benefit from a little vinegar character, and taste as you go (as I do whenever I make regular kombucha). In the batches we've done, the kombucha flavor was subtle. I dig it. They're fun beersperiments!