I was going to get the 500GB WD blue sata 2 @ £39.99 but for £5 more I can get the WD black 500GB (only became aware of the black from someone else's thread) with 32MB cache. Does the double sized cache make a noticeable difference?
The cache can make a difference, but there is a lot more to drive speed than the amount of cache it has.
The WD black is a faster drive all-round, though.