I realize this is an old post. But, I just ordered, received, installed and started using the Givi Monokey 52L Trekker case. So far, I really like it. My plan is to use only this top case as my day to day commuting and grocery getter luggage and probably a soft bag set up for trips and camping.
At first when I pulled it out of the box I thought it was huge. But once I put it on the bike (2001 R1150GS) it looks like it fits right in. Not too big, not too small. The locking mechanism works great. etc... I had it in a HUGE rain storm (the one this past Saturday night) and everything stayed dry inside.
I got the SW-Motech steel rear rack (
http://www.twistedthrottle.com/sw-motec ... ture-00-06) for my bike and the Givi mounting adapters for it. I liked this one because it was metal, looked nice, and had holes in it so I can still strap stuff to it if not using the top case.