Groove Doctor, I've only used the ISP Stealth on my pedal board in the studio. So I'm not sure how loud of a gig it can handle. But it does get very loud (with guitar) in bridged mode. For bass, I've tried it with the CN112, ML112 and the Thunderchild 115. Sounds great with all. Voicing is very neutral and transparent.
At low volume with Monique I'm actually starting to prefer the ISP over the other power amp options I have (Minnie, Crest Pro-Lite 2.0, Puma 900), IME so far. It's slightly leaner sounding, but it has a certain clarity and roundness to the notes that the more powerful amps don't really give me as much of, at lower sound levels. If that makes any sense.
But regardless of the power amp, Monique always sounds incredible IMO.