CAUTION! Buying baby car seats can be complicated, read a guide first to find out what you need and if this is for you! This is rear-facing ONLY, i-size compliant, for children 61-105 cm (approx 6 months to 4 years).
Normally £369.99, currently £40 off at Lesters Nurseryworld, I've seen them drop it to this price once before but otherwise I think this is the best price there has been on this chair. Most of the big, rear facing isize seats seem to be in the £300-400 range but this is one of the best rated ones out there at the moment.
Which summary review (no login): http://www.which.co.uk/reviews/child-car-seats/besafe-izi-kid-x2-isize
I've owned one for a month, it's a bit fiddly the first time you install it but you get used to it. It's also heavy. I swap it between two cars twice a week, it takes no more than 5 minutes once you know what you're doing. You can adjust the leg space for your child, I've found at the maximum setting it leaves 'enough' leg room in the front passenger seat in a medium sized car, but it's quite tight in a small car. Unfortunately there's not much you can do about that with rear facing seats. The optional side impact attachment is a pain to fit the first time too but again you get used to it.