I've had a brake on my seatpost before on a bike that got stolen, but I don't plan on doing it for my current bike. I find it aesthetically displeasing, not to mention I have non-machined rims and I don't plan on ruining them. I'm not trying to sound like some proud and reckless tarckstar who rides brakeless for street cred, it's just that I've put a ton of time and money into making my bike exactly how I want it, and that's how I want it to stay.