i ride as hard as i did when i had a brake, if not harder. i've always been extremely cognizant of what's going on around me, and don't feel like i need to have some sort of "oh ****, i made a poor decision" lever to keep myself safe. even with a brake, i've always slowed down before potentially dicey intersections to get an idea of the traffic pattern and to look for ways to get through without problems. personally, i think it's better to come up to a busy (i still bomb the **** out of most intersections) intersection slower and able to take in the scene than to blast right up to the line, hit the brake, and then check and calculate. i've seen this particular thing a lot in alleycats and it really puts such people at a disadvantage.

this all said, you can ride intelligently with a brake, but the brake isn't going to help you out much. i can agree, though, that a brake will probably allow you to negotiate larger hills more aggressively.