The one I took out had Bridgestone. So I though ohh yeah cheeky buggers swapping out the tyres on their demo bike so checked on the repsol in the showroom and that had Bridgestones too. Didn't get the model, bit maybe there's a change.
55 on mine and no complaints. Can't compare to the standard 50 profile, though know at least that the speedo isn't now miles out now I've gone up to a 44 tooth rear sprocket too.