tires are what are going to stop the vehicle. It's like upgrading the intercooler on this car, a larger mass provides more storage for all the heat energy, so it doesn't warm as fast when the energy is being dumped into it. Being larger there's then more surface area to shed that heat into the atmosphere more rapidly. The question is, when do you heat soak the IC, or brakes, to the point that they lose effectiveness. Depends on a bunch of things, which is why stating a BBK is needed is poor advice.

And the bit about the stock brakes being sloppy is purely personal opinion. If that were the case stainless steel brake lines would be a better upgrade than doing the entire big bucks brake upgrade to try and get rid of perceived sloppiness.

National Motorists Association