Okay, some initial feedback on the PF500!
Keep in mind, the info in this post is with
headphones only, until I can get to the practice space in a few hours and hook it up to my Avatar B210. Obviously, no headphones can reproduce what cabs can do.
I plugged my bass straight into the PF500 and powered up, and immediately knew I'd like this amp. Even just through headphones (earbuds I use as in-ear monitors... not ridiculously expensive, but not cheap either), it has a
great bass sound. My Jazz V sounded more like it usually does through my
live rigs, which surprised me quite a bit.
The controls are great! If you've been following this thread, you know what the PF500's got, so I won't bore you all with "This is the compressor, this is what it does."

With the Ultra Hi/Ultra Lo and Mid Frequency selector switch, you can really dial in an impressive variety of tones with this amp. With all the controls flat on my bass, I was able to dial in all sorts of sounds... scooped slap, motown, Jaco, etc.
Pushing the gain up led to more aggressive overdriven tones, of course. I won't render a final verdict on the overdrive sound until I get to the practice space, but right now I don't feel one way or another about it. It didn't sound fantastic, but it definitely wasn't bad either. Maybe it'll sound better through a cab? I suspect that I'll probably leave overdrive duties to pedals on my board though, like I do with my Shuttle 6.0.
I'm pretty darn impressed with the PF500 so far, and I've only spent about an hour with it in my apartment, just using headphones. The real verdict will be with an actual cab of course, but so far it seems like a VERY versatile amp!
More solid info (and hopefully clips through the cab) to come later...
5sg.