I don't like Riff much, having seen several of them recently. The banter thing becomes really annoying after a while (like Top Gear does hi-fi somehow) and they do make suprising mistakes. Darko seems a bit of an arriviste and occasionally goes yapping after whatever the latest fashion is.
I have more time for the Americans (Fremer and Guttenberg), but I have about as much faith in the reviewing powers on show in any of this as I have for mag reviews; namely it works as a kind of in-depth advert, but mot much more.