In reply to andy.smythe:
I've a Cylq from Lightwave that's very similar to the Hyper T20. It's had well over 100 nights of use and has been absolutely amazing. The groundsheet now leaks if I pitch it on saturated ground, but I'm actually going to get the floor replaced rather than buy another tent - the rest of it is in that good condition. I'd thoroughly recommend the Hyper, and the venting in it's very good. The poster above is right that it's not free-standing and is more reliant on pegs than a full geodesic, but I've never actually found that a problem.