I'm off to Cardiff next month and reckon the standard is good there, a mate of mine opens the batting with me in the West of England Premier 2 league, and he didn't even make the 2nd XI at Cardiff...
Surely not? I've just finished at UWE, played against both Cardiff teams indoor and out for the last few years and they really aren't all that great, particularly the 2s! They do play a decent standard to be fair but nothing special, someone batting at that level for their club should definitely be in with a shout for Cardiff 1s. Our 2s have been in the same league as them for the past few years and usually have a pretty poor batting lineup!
Bath have usually been fairly strong when I've played against them, again nothing to write home about though. Not sure what league they're in these days but their 1s are usually a very good side, down to their 3s who aren't.
Uni cricket is a strange business, because selection is usually done by fellow students (apart from at the very top level) and based only on nets/whether they like you or not, a lot of good players can slip through, especially when you don't actually play and proper cricket till the end of the year. Commitment to the club will help you a lot as that's often what committees will be looking for. Also very hard to predict the standard as there's such a high turnover of players - a uni side can easily go from superb to poor in one year if a lot of top players graduate together and it happens that the new intake isn't very strong.
Highly recommend getting involved in uni cricket though, particularly somewhere like Bath who should have a strong coaching setup. Even if you don't make it into the 1s/2s the amount of training/coaching you'll have access to can improve your game a lot, I know it did for me. And of course the social side is great if you throw yourself into it.