just to re-iterate, I bought the Wiggle own brand shorts for £18 as a test for commuting (so about 45 minutes quite hard effort).
They are cut quite high at the front, so not great if you are out riding and need the loo.
The leg grippers are quite tight, but the marks fade after about 30 minutes, so not terrible.
The pad is pretty good, but it's not vented, so in hot weather you are going to get sweatier than with their fancier vented pads - however, it's really comfortable, good for two or three hours probably.
The lycra seems thick, they're well cut, not too many panels and mostly flat-locked seams.
For £18 I can't see where you could go wrong.
The DHB classic at £45 is a much nicer short, with much more supple pad, very smooth and comfortable cut seams and leg grippers, really airy bibs, cut lower at the front - altogether a great short, but it's nearly three times the price!