Finding out how Mikrotik proprietary WiFi driver had some serious quirks. Aside from being ACv1 they had some untenable problems with interference.
Some agreement here but as another thread on this subject has said, Mikrotik focus does seem to have been more in the enterprise router/switch space and the wireless side has long been the poor cousin.
I too had trouble with a small but interference heavy environment in a pub. Never fully understood if it's the driver/software or hardware or both. They have done a lot of work recently in v7 on the wireless side so I'm hopeful that sleepless nights worrying about installing Mikrotik wireless are a thing of the past.
In your particular scenario, I'd be personally tempted to put a UBNT P2P NanoStation link in and a local access point. Only say UBNT because I have zero experience of Mikrotik's PtP offerings and UBNT is rock solid and easy to set-up.
Ohh hang on, the picture isn't the original poster is it? Still for 120m, I'd still be suggesting a PtP link. I've got a client with a caravan site with two UBNT external access points. Not really powerful enough and we're considering more.