I think the thing with ABS is that it is a safety issue. You can't really determine when you will need it. It helps a great deal even on dry pavement in a panic stop situation. I had ABS on my FJR and it came in real handy a couple of times and no water anywhere near where I was. Turning it on and off defeats the purpose.
As far as choosing the R3T over the Roadster, I don't think I would trade mine for the new roadster. Yea, it has all the power, pulls great wheelies and burns off tires, but let's face it, how often are you going to smoke the tires before the cost of tires starts to get a little irritating. With a couple of mods to the R3T, I can smoke tires and pull wheelies also and I still have the bags and windscreen. I wonder what insurance cost differences will be between the two also.