**Update** ... its been a while
Dorman axles are still working at 230K miles now. I changed my diff fluid again a few months ago and things still looked nice. No play around the wheels. The magnet at the bottom of the diff really helps. All of the fluid around it was nice and clean, only the last bit that drained out had any darkness to it. That puts them at 60k miles so far.
2000 P71 - Mostly stock. Shark Plenum, 70mm TB, Flowmaster exhaust, NGK TR6IX plugs, Steeda Underdrives, 21mm rear sway bar, 23x,xxx miles
2008 Buick Lucerne CXS - Sold
2001 Cadillac STS - Sold
1988 Buick Lesabre T-type - Sold
1990 Buick Lesabre - Rust
1989 Buick Lesabre T-type - Rust