I have been on a few of these deals - the last to Rome in Feb. They advertise one of the cheaper hotels but you can select others. We stayed in the Intercontinental. I booked it in December when they had the Xmas offers on - £880 for two for CE and 3 nights which I thought was pretty good.
If you're just looking for cheap flights then stick around here. There was a 25% off CE offer on that has sadly just ended. Usually after Taste of London there is another offer (10% off all flights last year) as well as all the various sales.