The passenger makes a HUGE difference. I have a coworker that is a wonderful passenger and we've gone on long rides. She is tiny and light, but she is always paying attention to the road and gets involved in the riding, while I do feel she is back there, the bike does behave perfectly. On the other hand, my ex-wife, which is also a petite female, is a terrible passenger and I hate riding with her.
Heavier passengers? I don't think so, the Versys becomes WAY too much wheelie happy and too light on the front end to my liking.
Space I think is fine, I don't have an issue with that.