Sorry about the novel, but you wanted a report so here it is. I put the bags on Friday and used them over Memorial weekend.
Quick answer is, I like them.
The tank bag is pretty good sized but not too big. When it's expanded it's pretty darn big. In either mode I can still see everything on the dash (I'm 6' tall).
The piece that the bags zipper to, that straps down over the gas tank, fits pretty good but not perfect. It actually fits real well and lined up until I put the side panniers on and strapped them down. When I did that it pulled the filler hole a little forward (towards the headlight). I can still get gas in, but the hole being forward won't let the gas cap come all the way back without holding it back with one hand and the other hand filling the tank. All this while holding the mostly unzipped tank bag forward with my elbow. Either that or totally unzipping the bag, which I found to be a PITA. The bag is not hard to unzip or reattach, but finding a place to set the bag down and reattaching it everytime is just too much BS for my liking.
The 2 straps that attach to your bike under the seat work pretty well. They could be resewn a little higher onto the protection pad and would work better. If you're using the stock seat the buckles just barely clear over the top of the seat. With an aftermarket or front padded seat you may have to move them. I don't believe this would be difficult at all, if you need to.
Filling the tank as I described is not that bad and became easier as I did it more often. I have a friend who does upholstery work so I can get him to enlarge the hole back toward the seat a little bit. Then I will only have to fill the tank with one hand and hold the bag with the other.
The panniers actually will hold quite a bit of stuff. My only real complaint with them is, the zipper is hard to work in the corners. Again with a little practice and different technique it became much easier. I wasn't sure if I was going to keep the whole system or just resell it and order the versys specific bag , so I didn't cut the leather tabs that I presume are scratch protection for the BMW. As it turned out they are not in the way that much, but there might a little better clearance around the turn signals if I do cut them off later, and would probably look a little cleaner also.
I have the H&B bars, and the panniers strapped up pretty good but you will have to take the Famsa straps off and replace them with 1" wide webbing, 2 per side. A different set of bars will probably require the same thing, not sure.
I really couldn't tell much difference in wind drag (with the panniers on) when riding the bike at speed on calm or breezy days. When the wind got up to 27-40mph I believe they were causing some drag, especially in a head wind.
I have DVT in my left leg real bad. So when the wind whips your pants back and forth, its like someone slapping the crap out of my leg nonstop and after a while it really gets to hurting. SO....an added benefit to having the side panniers on is there is NO turbulence on my lower legs and I couldn't quit smiling about that
I also put highway pegs on, due to my leg and I have just enough room to clear my shin bone and the back corner of the panniers. Most people would put the pegs in a lower position, but it relieves the pressure on my leg if they're up higher. I don't see the panniers causing a problem if anyone wants to use Hwy. pegs.
The Famsa system (w/side panniers) is not a perfect fit but darn close and with a little tweaking can be just about as good as it gets without being made specifically for the versys which I don't think they're going to do. Also you could leave the panniers off most of the time and just put them on for trips and such. I have decided to keep them and all in all I'm very happy with them