on my 2001 525i, i got sports seats, manual ones. im actually glad they manual. less problems...
on my previous ride i had a e30 325i, which i fitted front electric sports seats from a 1997 M3.
i eventually had one of the gears stripped, was finnicky to replace...eventually replaced it though.. when i sold the car though, the driver side seat gear also had a problem (the dredded e36 electric seat recline gear)
i had no idea e39 electric seats also gave issues... again..hehe im glad ive got sports seats of the manual variety (has up/down,tilt,recline,forward/back)