All brakes are engineered for a certain situation and to exercise a specific coefficient of friction on a brake drum or disc. Under normal circumstances, the brakes designed for the application should be sufficient for normal use.
Now, the problem often arises where brakes don't perform to specs and overwhelmingly the most common cause of this is brake fluid that is not doing it's job and this is governed by age, type, quality and use. Brake fluid absorbs moisture and for every application of your brakes, degrades in performance. Hard frequent use will effectively 'wear' out your brake fluid.
Just as common also is the situation where brakes are not adjusted properly. I've seen this so frequently on all types of motor vehicles and this is so important.
These two things will effect your braking ability and if you have changed your brake fluid and adjusted your brakes properly, you shouldn't have any dramas. As someone esle has already mentioned, perhaps a greater braking ability may induce other problems ie, grass strips etc.