87 535is Tranny problems

[DeepPurpleFan]

Just bought 87 535is, 1k later, tranny is shifting funny:
1) Sometimes it'll hesitate between gears - a split second bog down, as if it gets stuck in limbo between gears. There are no grinding sounds/scary noises or hard jerks.
2) Sometimes it'll shift somewhat hard, with a jerk, but without hesitation. No noise there, either.
3) Sometimes it'll shift just fine.
4) There is a clunk when I put it into reverse.

Now, there is the funniest part. The car has only 100k, the previous owner changed tranny at 69k in 99. I have receipts.

Would it be a good idea to run computer test at a BMW dealership, and then do work myself/at a cheaper shop?

Thank you!!

[pashtet]

Sorry, wont do it again.