Re: disc brakes....?
If you think about it all that a brake is doing is turning one kind of energy into another(forward motion of the car turned into heat by the brake). So, the more energy that needs to be dissipated the more complex the brake has to be. So,vented discs on the more powerful models that might call for more braking efficiency. To get optimum performance the pad lining material has to be matched to the design of the brake so even though a pad might fit it does not necessarily have the correct or original lining material on it. All a bit marginal in daily use though I think.
I've tried drilled and grooved discs on cars at work. The green stuff pads seemed to need a bit of warm up time, but overall they did last longer than the standard ones. Overall I would say they did what they claimed to, you just have to ask yourself whether you really need to spend the extra cash.