It runs okay, seems to have the same problem as ORAS and USUM though, lots of hanging going into battles. I personally wouldn't be able to finish the game dealing with that. Right now your phone is the better option.
I'm getting really bad slowdown with Omega Ruby, especially when entering battles. Overclocked with RA and with Sysclick. I don't get it, because in all the gameplay videos I've seen ORAS seems to run great.