No that is not a problem.
People tend to do so because "they should". But extra hp doesn't mean the car is heavier, or that you will drive at higher speeds (standard Z can already do 250 km/h, which is more than I would advice on any public road, given the state of some of those roads), or that you suddenly will be doing 0mph - 100mph - 0mph all the time. And standard brakes on the Z arent exactly crap either
Did I met mention anything about weight???
Increase bhp you increase speed therefore the faster you go the quicker you need to stop!!!
Ok I see your point in relation to the zed... NOT out of personal (and without naming names) experience I know the std brakes and disks to be iffy when pushed, trust me I know they can't cope