I still kick myself for selling my 1988 R100RT - it was very comfortable to ride. While it didn't make you feel "sporty", it could pretty much do whatever the RS could do, except it was a bit heavier and slightly slower on the top end - mostly all due to the larger&heavier fairing.
I haven't owned an RS but have ridden a few - they certainly make you feel "sporty" but I gotta think that the more forward leaning position may get more tiresome with that efficient RS fairing keeping all the wind from blowing on your chest, helping to keep the weight off your wrists.
I'd personally prefer a R100GS over the current production R1200GS or older R1150GS Adventure bikes - they just seem waaaay to huge and heavy to want to muscle through loose sand and dirt, and if one tipped over in such conditions one would have quite a time righting one of those beasts - the R100GS is more "practical" as an occasional off road bike, in my opinion. But, the paralever swingarm design on those had some issues - I think mostly resolved or resolvable by now with rebuild kits. Of all the models in your list, the R100GS Bumble bee models tend to hold their value the best, while the R100RT hold value the least - if that is of any concern to you.