Would second everything that has been said. I've had my 33 Mk II for a year now and am very satisfied. Took her to Cherbourg and St Vaast this week - some excellent sailing and quite a lot of motoring. I went for one that had been well looked after and upgraded - suggest that you go for the same and pay more money.
For - space, siffness in a breeze, solidity, ease of handling, quite fast enough for me (Thornycroft T90 gives an easy 6 knots, and she sails in F4+ at 7k when properly trimmed), great aft cabin for the kids / workshop (depending on your situation), flared bow means quite a dry boat. It takes quite a lot for her to slam and I find her very seakindly in a big swell. Most have the original thumping engines - reliable and strong, if well looked after.
Against - needs 12k+ wind to really go, engine access difficult (but by no means impossible when you've worked it out), would like a second sink and a proper double berth / separate aft cabin if I was being picky, bilges sometimes a bit wet (fresh water getting in somewhere), engine not the quietest.
You should get a good one for £28k +. If I had more money i'd have gone for the 336 - more modern and better thought out. But for what you pay you get - they are a great boat and I would really recommend them. They are ageing well.
I'd be happy to answer any specific questions - do pm me.