I used The North Face Tadpole last summer whilst researching the Wales chapter of 'Cool Camping Britain', and found it stood up to everything the worst summer in 100 years threw at it.
Weighing in at 2.37kg and packing away to 53cm x 15cm, it provides you with the options of free standing and fly-only pitching if you really want to travel light, whilst erection can be done in under five minutes with a bit of practice.
Stability is good, as is ventilation, meaning two people can sleep comfortably albeit snugly in the Tadpole, with space in the vestibule for packs and useful overhead storage pockets.
Build quality is high and although marketed as a three-season tent it could be used year-round in most UK conditions.