Re: PATB-1 dark?
I'd say the opposite. Bright, but not harsh. Accentuated harmonics without the sizzle or mid to treble spike of many pickups with that behavior.
Bass is definitely tighter than with a JB in my '90 RG570, it's brighter but less harsh. Sweet pickup, but very far from syrupy. A lot less mids to upper mids, but not lacking in upper mids.
Open, woody definitely fit as descriptions. It'll have a lot less mids than a Custom Custom, be more open, higher output but feels less hot due to the reduced mids (compared to the A2 pickup with similar wind).
It's actually louder than the JB was in the bridge, but clearer in my guitar. I love the pickup, it's far more flexible than the JB (which I'm using with A3 as a neck pickup, which balances surprisingly well).