I'd echo what Paul's already said
B12's a great bit of kit, i've had it on for nearly two years
No first hand experience of the H&R kit, i know a guy who's running it and he rates it highly
EDIT: I suppose it's worth bearing in mind the early B12 kit is made with H&R springs anyway,
so don't think there a million miles apart in terms of performance
(could be talking out of my a**e though)