Ok, it's time to see these things in action...
Hi Till,
again, thanks for your considerations and thanks for your help!
I think it's time to actually have a look at these bags in a store - will try to do this once I get back to civilization (currently on the road).
I was thinking of the spinner issue and came to the conclusion that if I'm in smooth terrain they should be much better than then non-spinners. In rough terrain (I mean really rough) I'll have to carry to bag anyways. Thinking back to the place I go, I think it is probably either "spinner friendly" or "too rough anyways" so I think I will have a closer look at the spinners (the times I used to drag my bags over miles of cobble stones are over).
Then, actually this exchange got me start thinking of a briefcase, too (I know I said I should be covered, but maybe it's time to upgrade that, too? Anyways, will start researching that topic (especially the new TSA "approved" bags)
Ok, will let you know what I ended up doing.