Here's the test results I promised last week. During a rehearsal I tried 3 different amps on a pair of SWR Goliath III cabs (4x10", 8 Ohm each).
YES: Driving a 4 Ohm load, the Soul II is loud enough to make itself easily be heard in a loud band.
BUT: At high volume the sound quality degrades noticeably, even before the clipping LED of the power amp lights up.
So for myself I'm ruling the Soul II out. As I mentioned before, my band is quite loud - for a band with more decent volume, it would be my first choice.
The Heart-Rock II sounded great, and it has more than enough volume for my needs. The only reason why I did not buy it straight away was my third amp under test, a Mesa Boogie M6. Although it has some flaws (significant preamp noise even with decent treble settings, loud fan), it has such a rich and lively sound, especially at the low end. I immediately felt comfortable with it.
Haven't made my choice yet, I wish I could get them both
