I always go for the L-bracket. The first time you are shooting on a tripod and can't figure out whether to shoot portrait or landscape, it'll be worth the money.
I always use Kirk L-brackets. Why? My favorite brick and mortar store sells Kirk, I got one many years ago, and I've always liked them. They've given me no reason to even try anything else, so I haven't.
Frankly my experience with RRS has been that they're excellent too, and my guess is that if they had sold RRS instead I'd probably have the same story with the names changed.
At this point I have Kirk L-brackets for five of my cameras, as well as Kirk lens plates for five lenses.
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!