not really any help since i got such low miles but i thought i'd add.

2003 SSEi
almost 32k on it
put an accumulator shift kit and partial fluid change since pan was off.
mods in sig.

97 SSEi 65-HD - 184,500 - Still Strong
97 SE/SC 65-HD - 163 something - Still Strong

1998 SSEi - 184k with clutches starting to go, pressure control solenoid was also failed.
2001 SSEi - 38k, replaced for some reason, (I did not own the car then)
2001 SSEi - 82k on the trans, and it feels pretty solid.
2000 SSEi - 4th shaft failed around 120k, Everything else was ok at 160k when I sold it.

My 99 SLE is still on the original transmission with no rebuilds after about 123K miles. The transmission fluid had been flushed every 30K miles up to this point, but we have yet to flush it for the 120K mark. It feels really smooth and strong when it shifts.

I just had my 2003 SSEi transmission rebuilt as it went completely at 88K miles. I am the original owner and have babied the hell out of that car. The final drive went out. The transmission guy (who is highly reputable) said he has only seen 1 other 4T65 go out like that. It is usually the lower gears that go due to abuse. I chose to rebuild as it was 1/2 the cost than to replace. It started getting loud, then slipping then blew - sheared all the teeth right off. Rebuild took 1 day once they located the parts.