I looked at these - they do seem to have good reviews. The price wasnt that much difference per year when I had added all the extras on to warranty direct so decided to go with Lexus - at £600 a year and so far no quibles. Had a drip appear on the pipe of the water pump, whole water pump replaced including fluids etc, flickering headlight 2 x complete headlight units replaced. There was no delay, it was just done completely FOC and valeted.
Lexus currently charge £760 (12 months) or £1335 (24 months)for the extended warranty on the IS. If I remember rightly, Warranty Direct was around £500 for the same level of cover. You also have the option of a Lexus garage to carry out any work, for a few quid more. I also dont need the breakdown cover, as I get this as a perk, through my company.