I think for heavy domestic flyers the RCC is a must even though I always complain the clubs can do better (because I believe they can) they are still a big help during irregular ops and doing a lot of time at ORD like I do they are nice because I can usually get a seat at the bar (which is very difficult at any other bar at ORD) and I can get pretty good and quick help in the case of any flight problems that come up and if you fly domestic and more specifically ORD enough it will happen. I think the same can be said for IAD.
I dont think you will get the discount based on future travel. As far as snacks, there typically is just enought to prevent you from saying there isnt anything. I do some time in US clubs and honestly....UA blows them away in that department so it could be worse even though I like the decor and atmosphere in the US clubs much better. I can deal with the snacks issue if they would just provide wifi but I know that will not happen as tmobile is probably giving them too much kick back to keep it.