new wheels - Fulcrum dark label or 303's...?

If you have already narrowed it down to two (and not exactly all rounders), I guess you are not that open to suggestions, so I will pass.

BTW: you should post this in the buy advice section

obvious comment: Zipp 303 RRP £2300. Fulcrum Dark Label under £900. So not exactly comparing eggs with eggs!

I actually own both, absolutely love the zeroes, have had two different sets and they have never let me down. Latest purchase was 303 Firecrests and, in spite of all the hype, they really are brilliant but you only get a performance benefit at relatively high speeds, at about 24 mph+ on the flat they just humm, even I can 'feel' the benefit but in the cold and wet and crappy roads at this time of year they are not my wheel of choice. Carbon braking surface and pot holes probably do not mix well. Then there is the issue of wider brake track and possible frame fit issues, but they fit my Venge! The zeroes will go anywhere and do anything.

In short If you shop wisely like I did you can get the 303's for £1500 and the zeroes for £650 you have actually spent less than the 303's RRP so get both!