The issue of what racks and panniers to use isn't as simple as it first seems. I asked my BMW dealer to fit the very heavy duty Tesch racks, on the basis that they reinforce the rear sub frame of my R100GSPD. They said that this is a bad idea.
Three reasons: 1) rigid frames are more likely to crack 2) in doing so they are more lokely to damage the rear sub-frame 3) they are more likely to break your legs if you get trapped under them. In fact, on the latter point they had doubts about the safety of big steel panniers. I suspect that is based on Ted Simon's nasty accident with Tesch panniers.
On the first and second points they may in facy have been proven right. I crashed at 85mph, running up against a motorway barrier so hard that a hole was ripped in the top of a Tesch pannier. The bike stayed quite up-right, leaning against the left hand Tesch pannier. The lightweight Hepco & Becker rails bent out of shape. There was no damage to the sub-frame, and the BMW dealer was able to bend the rails back into shape with no problems. Since then I've been over quite a few times off-road, and the rails are still fine.
Another tip. If you use a Touratech tank bag with side bags hanging down the side of the tank, don't pack a side bag with tools. I now have a permanently swollen left leg.
Am happy to be using only an Ortlieb dry bag on a trip to Africa in January. Lightweight is best.