Gigged my BG250-115 mk.2 for the first time last week, and it acquitted itself very well. The venue was quite a large hall, and the PA was struggling a bit to produce any significant LF in the hall (we're only using some Carlsbro 15" tops at the moment - soon to change). The BG250 had plenty of volume for stage monitoring, and could be heard well out in the hall providing quite a 'phat' bottom end sound. I think I might try a tilt-back stand to get it off the stage as it was causing some resonance / vibration on the stage panels.
The volume output was impressive for a single 15" cabinet, although a little 'woolly' and indistinct when pushing the master beyond 6. For its' intended purpose it will be more than adequate - the halll was so large that the drums weren't dictating the PA and backline volume (for once), so not surprising that it needed to be pushed a bit.
PA will be getting two 18" powered subs soon, so the BG250 will be for stage monitoring only.