I've got a Lowden O25 (had an O10 and traded it) and a Martin J-40 and both are excellent in different ways. The Lowden's a Loud 'Un (excuse the pun), Cedar top/Rosewood B/S and VERY full-sounding, great for finger-picking. The neck's a touch wider than the Martin and took some getting used to but it's a nice profile. The Martin's a totally different beast (that's why I bought it and not another Lowden), very balanced sound but not a loud as the Lowden. Both are very purty in different ways, and both are a joy to play.

I reckon when you're up in the £thousand-plus region they're all good - just a case of finding the one that's the 'goodest' for you. No one else can tell you what YOU like - try them all and make a decision.
Johnny.