Iwan Bogels wrote:I'll decide what to bring (or leave home) before each individual trip....
Same here, though I must say that after using my new gear (carbon tripod plus ballhead with quick release clamps) for five days the monopod will tend to be forgotton... Even tried panning on a plane in short traffic circuit ending at finals nearly over my head, and to my surprise I found that easier than with the monopod.
The difference: with the monopod you gain stablility, but you still have to balance it. When panning, the ballhead is the pivot with a tripod, whereas you have to lean and turn around the foot of the monopod in such a case.
The tripod allows for steady shots, even after taking a sprint. You have to have light weight and quick setup for that though, which means pumping in cash.

I found it worth the investment.
As for VR/IS: Nikon advises VR
off on tripods,
on on monopods. This matches my own experience with stability. I tend to reserve the use of VR for when I need it anyhow, and usually have it off while panning (because it interferes with repositioning the subject in the viewfinder). Recently, I even ruined a few shots where I accidentily left it on while panning at high shutter speeds: parts of some images were blurred, and I can only relate that to the VR. It must have interpreted the dynamics of the subject as vibration, and tried to correct for that.
Erik