My rear shock is on its way out (1989 K100/2).  The bump stop is crumbling and the seal is just starting to leak - it's only low mileage but it is 26 years old.

I have read that some people have tried the YSS MZ 366, but was wondering about the YSS ME302-350T-01-8-X.  Just look at the price:

http://www.ebay.co.uk/itm/BMW-K-100-Federbein-YSS-Stosdampfer-YSS-7890123-/231563693910?pt=LH_DefaultDomain_77&hash=item35ea458f56

Has anyone tried one of these?  Are they up to the job?  I'm not looking for anything special, just something that works as well as the original.

Think I would save up for a Ram shock or, for similar money, rebuild your old one with a new Bilstein damper from James Sherlock.
Not difficult to do.

Thanks for that, I didn't know about the Bilstein damper as an option.  I have done a search and found your instructions on the dismantle/rebuild.  Very useful, thanks.

Way back when, both YSS and FVQ had a very poor reputation, so much so that even today I wouldn't buy a YSS shock. As for FVQs... Fade Very Quickly sums it up.