I have an '87 GL with 154k miles. The AT was rebuilt at 143k miles and 
going strong.

As far as power, I'd say that driving a 4speed may give you the 
impression of having more pep, but the AT does just fine.

As far as problems, the only thing I know of is what happend to me. The 
AT Fluid cooler had an internal crack and sucked engine coolant into the 
tranny at 137 miles. I made several quick and successive transmission 
fluid changes but I am sure this caused the failure at 143k miles. Local 
AAMCO guy is also a VW guy and did a great job. The tranny shifted a lot 
better and was less sluggish than it ever was since I owned it (bought it 
at 98k miles). :)  Cost about $1400!   :(

Hope this helps.

Peace,
Rich Smith
rich@indy.net

VW Thing Association Prez
www.indy.net/~rich/vwta.html