I was there for a day this year ... wish it had been the whole weekend, one day was *not* enough for more than a cursory walk through the whole set-up. I was down there to meet with a particular manufacturer and to check out one of their trailers, used the excuse to check out the expo for a day ... definitely want to go back, though. Also, I'd love to try and get into some of the classes/seminars they offer if you're signed up for the whole weekend experience. Still up in the air about next year ... would love to try and make it, but not sure if it will make the cut with other potential trips on the list and (somewhat) limited PTO.
As far as the timing, if my memory serves (questionable, at best) the last two or three years it has lined up with the preceding weekend to GONE Moab ... totally seems feasible that one could take off mid-morning Sunday from OvEx and make Moab in time for the M&G Sunday evening. That is, of course, if they both keep to traditional schedules ...
Quest, that Scenic Drives tool looks pretty cool ... may have to play with it some more. What's the sign-up cost? Any negatives so far? Like spam, expense, excessive ads, etc ...
Also wanted to note, that the expo is held here:
http://goo.gl/maps/QX99w, unless they're changing the location for 2014 ... it looks like maybe a slightly different spot than you have called out in your Scenic Drives maps.