haha. i thought that too.. they are flexy though, i ran some on my cannondale for a bit, but swapped them out. i got a bum front brake though, i greased everything, bedded them in nicely, and they still wouldn't stop squeeling
I have the 555's. They're pretty much the same thing. They're black all over and don't say Deore on them.
They're the best brakes I have ever ridden.
Front one hasn't been bled in 5 years, and they both feel great. I've used them on the DH bike at Northstar, Mammoth and Big Bear without any problems, and they permanently reside on my Enduro now.
The pads will wear out in 3-4 months of regular riding (say about 1000 miles). If there's any mud at all, expect pad life to drop significantly. On the plus side, riding the low-end rotors with very few holes in them means you can ride without any padlife left, and your scratched rotors will still work just fine once you get new pads again. There just won't be much stopping power.
I got some (Aztec?) stainless steel lines, and can't get them to connect properly to the calipers. I'm losing fluid. Every month, the rear brake needs to have more fluid added.
Get them 535's. They're great brakes. And cheap, too. The levers/rotors are compatible with more powerful calipers if you ever want more power. Which you won't.