I first got a deal on a set of off-brand SPD clones; worked, but short-lived. Then I got a pair of 515's (several years ago); better action, and MUCH longer life! I still have them, and my daughter will be inheriting them!

I ride Time ATAC's now, and will never change, as long as I can get them. But if Time's weren't available, I'd run SPD's in a second!