i just discovered the COB powertone in the last year. bought a decent condition mid-60's on ebay. i dont' know if it's the lack of snare beds or what, but this drum is the easiest tuning drum i've ever had, and it comes closest to sounding like the sound i have in my head than any other snare i have (and i have a modern black beauty and 70s supra and supersensitive).
I have to say you're on to something. I got one a month or so ago, brought it home, tuned it relatively quickly and bam it sounded great. I haven't fiddled with it endlessly or tried coaxing it into a sound I was looking for because it already pleased me.
Troutstudio's descriptions were nice. I don't own a BB, so the sound characteristics of a Dyna and Powertone are much closer in my memory than that of a Black Beauty (9 gigs in the last 10 days on one or the other Rogers). I definitely find them both very funky, especially with a good dose of tone control. Wide open (muffler disengaged) both the Dyna and the Powertone seem drier and fatter when played dead center with less brass ring, but the Powertone has more guts and bottom end. The Dyna is precise like a sports car, symphonic in feel and it's almost work when you want to sound sloppy like a 2nd line feel. The Powertone is more forgiving.
Maybe one day the drum gods will drop a BB in my lap but for now I have other fish to fry. I'm very happy with a Supra I just scored and these days I don't have a wife to tell me not to make crazy purchases so I have to nag myself...
Btw, I still can't figure out how to update my signature as my list of gear is quite out-dated (sorry for the OT)