5miles,
I'd say that there are probably more CFM-engined 320's in the UK charter business than the V2500. This is mainly because the CFM has a better field performance than the V2500 (ie) one can get more weight out of a small greek island strip on a hot day thus can get back to any UK a/d without the need to techstop, as was sometimes the case I believe with the older V2500's (before my time on the 'bus).
I wouldn't like to guess who uses what as that would result in howls of protest from all quarters; suffice it to say however there are still plenty of V2500-engined 320's in the UK , and some might say that it is a far more refined engine, but that's another matter!
DCD