I've always felt the 4-speed manual trans (091) has struggled to keep up at
freeway speeds - I've got 250k on mine and will be looking to rebuild or buy
a new one soon.

I understand VW made a 5-speed (094) manual transmission.  I have several
questions that some of you may be able to answer:

1)  Does the 5-speed let you drive freeway speeds without redlining the
engine like the 4-speed?
2)  Are there performance negatives with the 5-speed vs. the 4-speed?
3)  Is it interchangeable with the 4-speed in terms of engine bolt up, shift
linkage, and so on?
4)  Are they hard to come by?
5)  Are they expensive?

Thanks,
Gary