I have a BB-5500 with only 1100 miles on it, and the drive side seal itself is completely gritty and noisy.
I have futzed with it a great deal and concluded, based on the frequency of the noise per revolution that there is not much grit in there but that a small amount makes a big difference. Since reading this post I tried to pry the right side seal out with a tiny screwdriver and could not do it. I was wondering if I might get a few more miles out of it if the grit is in fact confined to the seal itself and has not made it into the bearing. My RS seal does NOT look mangles at all, it looks mint.

It is worth noting that I have never had a BB become degraded even this far until nearly 3000 miles, including a very cheap BB-LP28, which is a very low-precision boat anchor of a BB, but rolled OK for longer than the BB-5500. My Campag AC-H has 4700-ish on it and is smooth as silk though I upgraded to true Centaur recently.