The superiority of soft luggage on these kinds of trips is well argued by Walter Colebatch. I couldn’t agree more, and also ride with Adventure Spec Magadans. I used to prefer to have them the wrong way around though, with bottle pockets facing backwards. This way I could keep my extra gloves and rain gear in the front pockets, without them getting too dirty. On long trips where I need to carry bottles for engine oil and air filter oil, I keep the bottle pockets in the front. I’ve added bungee loops on the pockets to secure the bottles.
As for luggage racks, my money is on Rally Raid soft luggage racks, which I’ve said before. You do have to be careful with the RR racks though after falls, because they do bend. This is a design feature though, as the plastic deformation of the steel rack absorbs a lot of energy, instead of allowing it to pass directly to the mounting nuts on the plastic rear tank. While it’s a good thing in keeping the tail tank in one piece, the bottom of the rack will hit and chafe the swing arm eventually. So make sure to bend them back to shape after tumbles.
I use normal cargo straps with metal fasteners to secure the panniers to the racks. I used to have them lower, which resulted in the left hand pannier making contact with the side stand. This resulted in minor abrasions. The bike was felt a little more unpredictable in terms of handling as the luggage could swing a little while hanging low. There was also very little clearance for boots and in technical terrain I kept getting my foot caught between an obstacle and a pannier.