In reply to chaldakov:
I have a terra nova laser competition 1. It's good, and it's under 1Kg - packed weight is 970g. Sometimes adverted as lighter (910 or even 870 somehow) but mine is 970g, including the black pole cover. The cover is needed to make it fully waterproof, and provides two extra guy points which are essential in strong wind.
I've had mine out in strongish winds on the cairngorm plateaux. It's always hard to guess how strong, but 30mph at least, probably 40mph. It flapped about a lot, but it stood. The provided pegs are OK in good ground, if you're expecting wind you can place them carefully and put a rock on top in such a way that it keeps the peg down but doesn't chafe the guy too much. In snow or sand, you might need larger (and heavier) pegs.
Ventilation is generally OK, by removing a peg and lifting the edge of the outer, you can get a decent airflow through end to end. It is waterproof if pitched well, but poor pitching (due to uneven ground) and wind can combine to get the inner touching the outer, then water comes through. It's not trivial to pitch well, it takes a bit of practice to get everything adjusted so it's taut.
All in all, it's missing some of the comforts of a bigger tent, but I reckon it's pretty good for a 1-man lightweight tent. Shop about, I got mine for much less than the £330 advertised on the Terra Nova website.