I have an acquaintance who has a K1200RS. He has had it now for four full seasons and has toured it with great success. He is very happy with it. Despite the complexity, it has been trouble free for the 30,000 miles it has on the clock. He says the power is awesome, especially when carrying a full touring load and riding two up.
As far as weight, I have not ridden it, but it certainly does not appear to be as top heavy and clumsy as the K1200LT's I have seen. It seems to handle well at low speed in close quarters. On the down side, it does not appear to be as user friendly from a service/maintenance point of view as the earlier bricks, and the 2nd generation ABS doesn't make me feel warm and fuzzy.