In reply to poeticshambles:
Hi Poetic,
A reason that the xenons are less than perfect for sport climbing is the thin dyneema sling. If you get into redpointing a lot then you spend a lot of time pulling on the quickdraw, usually to pass a section you've already worked, to work the moves above. This is less of a problem with trad as you don't spend a lot of time sat on the rope anyway. For sport, having a chunky sling on the QD makes pulling up on them much nicer. This might sound like a small point, but if you're doing it a lot it makes a difference to your day!
If you're only just getting a rack together, then I'd not worry about this at this stage. Also, if you go sport climbing you're likely to want to do lots of onsighting, in which case you won't be pulling on the draw either.
As the previous poster stated, people tend to use short draws for sport, but you often need a selection of both for both trad and sport. I see from your profile that you're in Lancashire, the quarries there are fairly short, which means that you'll want more short draws, as extending is unnecessary and will bring you closer to the floor if you do fall off. When you're in the Lakes (as you also allude to) you'll probably want to extend things a lot more. Give this some thought before you buy any. As a guide, for longer trad routes I carry 6 10cm draws, 8 15cm, and 4 sling draws.