I managed to track down a copy of El Capitan over the weekend and updated. I then reinstalled OB and everything seems to be running pretty damn smoothly now.
A tip to anyone using Logic.. I would suggest if you are planning on updating OSX in order to get AH/OB working, update to El Capitan rather than Sierra. Staying on top of Apple releases can be a death sentence to compatibility and anyone using Logic 9 should be very wary of updating.
Hope you all get your issues sorted. It does seem as though it is primarily a 10.9 and 10.10 issue and should be rectified with an update...All your old plugins and versions of Logic being supported is another matter!