I got supplied an un-powered HotSpot as a key monitor in a live band recently, and I was very pleasantly surprised at how loud and clear it could go. But there's one big caveat... This was a full band, so my G70 wasn't doing the bass and drums, just the keyboard parts. So the lack of a full bass in the sound wasn't a problem - actually, a plus, because monitors really shouldn't have too much bottom on them, or the stage sound gets very muddy quickly!
The other thing is that you need to get them in as close as you are comfortable with, as this will let you run them quieter, and quieter means cleaner... So, a pair of these in the traditional arranger speaker position (just like a beefed up regular speaker-ed arranger, but angled at you instead of straight up) would probably do the job very nicely in a band situation at quite high levels, but I sure wouldn't want to use them as FOH