Both support routing, Mikrotik is more advanced then the UBNT gear. Any reason your not just bridging it all? Seems like this would be the easiest and quickest way unless there is some reason it has to be routed..
I have deployed a couple dozen MikroTik routers and I couldn't be happier. Happy enough that even the odd glitch that turns up (no brand is immune from this) doesn't discourage me.
What I still haven't done is deployed a complete 900 MHz MikroTik based tower yet, but I am certain that I will do that soon.
UBNT radio's seem to work very well on the RF side (except the cold temperature problem) but the frustrations with the lack of networking features on the ethernet side have me losing interest in them despite the low cost. If I had never been exposed to MikroTik, I might not have known the difference.
If I can get the MikroTik's to perform as well on the RF (900 MHz) side (there are plenty of people that say it does), I will abandon UBNT in a heartbeat.