I actually think Christian has more of an instinct of dictating the play from baseline than Ryan. However his serve and net game are simply not there, and those are both considered Ryan's weapons.
I believe he was known as a stonger baseliner of the two when they were young. I agree that he needs to work on his serve and netgame. I do like his backhand more than his brother though. Gamewise, I think they are very similar....too similar.