Had leather in my SL WRX Blob... was ok and not much difference with the normal seat.
Perforated too, so breathes and not sweaty.
Have had leather in a load of cars and overall would probably prefer it - although probably would like alcantara even better if only it didn't get dirty and tired looking so easily (ok when you're single but forget it with kids or if you wear jeans a lot).
Would agree that the best leather by a long stretch have been the Volvos, Range Rover and Jaguar... Audi and VW pretty OK too, but just not quite as nice as those others.
The only one I hate the leather in so far is the Hyundai... cheap hard stuff that is like an ice skating rink - even when treated with special products to give grip. Absolutely wrecks my back when I drive it between no frictional grip and no bolsters etc either. It's the missus' car though and in all fairness I rarely drive it and she doesn't seem to mind - and on the plus side it is extremely hard wearing and easy to clean when the twins spill stuff on put muddy boots on the surface when climbing in.