Most of their drawbacks to randomization apply to uniformity too, other than sites changing behavior due to your randomization. Uniformity has the big drawback of making it apparent that you're using the Tor browser, which is a red flag in some cases. At the very least it invites extra scrutiny. It's a strange design decision in my opinion to announce to loudly that a visitor is using the Tor browser when they presumably want to attract as little attention as possible.