RoR is probably one the most polarizing players out there, in terms of his actual on-ice value, and it is all depending on what valuations you use. Most GAR/WAR charts I see have him as a very valuable player, and those generally include faceoffs and defence metrics which obviously play a large role.
Alternatively, his 5v5 numbers are pretty suspect for a 1C, and some offense metrics indicate he is not anything special possession, entry or shot generation wise. Nevermind the crazy amounts of ice time he gets, relative to other elite forwards. Now, Buffalo was last place the last few years. It could easily be the poor teammates, chemistry, etc but I wouldn't label RoR a dynamic offensive talent personally and I don't really know where I stand on his value offensively. No denying his value on defense however, obviously pretty excellent.
I personally, as I mentioned pre-trade, would not have traded him until next season. I think he would have been a valuable asset given the team make-up, but I don't think this trade an utter robbery. The money has now been partially allocated to Skinner, I like Thompson, and the first can (hopefully) used to select our version of say a Robert Thomas. While I was disappointing initially on the return, I am pretty neutral now and think we just need to wait to see what we have in Thompson and the first round pick.
It is also pretty clear there was locker room issues, anyone who thinks otherwise is just kidding themselves, and that needs to be taken into account. So, all-in-all, maybe its a push, but could we have gotten Skinner without moving RoR? Who knows..