No - they're all the same, and you've got the 2 main differences!
My last 2 BA
Dash8 flights were on G-BRYJ and G-BRYV, and I noticed the same things that you did.
G-BRYI/J are the last remaining standard Dash8s in the BACX fleet, with the older cabin design but more importantly they don't have NVS (Noise and Vibration Supression)
The NVS system consists of a series of microphones and speakers throughout the cabin, the microphones detect noise, it is analysed by a computer which transmits an out-of-phase signal via the speakers - this has the effect of damping out both noise and vibration.
When you've flown both NVS and non-NVS aircraft close together it's very noticeable, isn't it?
NVS was made standard in 1996, so the rest of the BACX fleet have it, they even registered a couple of aircraft G-NVS_ to acknowledge it...
More info on NVS