Ryanb, I did an Open Air Checkout on a C172 in February. I travel a lot and wanted it to be easy to rent a C172. So far, it hasn't worked out to use Open Airplane for renting while traveling. If I'm just doing a sightseeing flight for ~1 hour, I'm happy with a CFII along as lookout, airspace advisor, radio frequency memory device, someone to take controls while I take pictures, etc.
I find individual, non-Open Airplane checkouts are typically 1.5-2 hours total, and much of the local knowledge is very helpful. I always ask about airspace, odd winds and things, stuff to see, and more.
The Open Airplane checkout was almost comical. It was at a local airport I fly from often, and it was the CFIs very first morning at work. I knew the area well, he did not. Neither of us had ever been in this aircraft before, and spent some time figuring out some oddly-placed switches. I don't think he had ever done an Open Airplane checkout before. We did some ground discussion first and went over some typical questions. The flying was straight forward - some pattern work, go arounds, steep turns, power off stalls, turns on point, TnG, short field, soft field, etc.
The Universal Checkout was an Open Airplane form the CFI used and signed off on. I have a copy of it and would present it if renting Open Airplane. It's good for one year. Their agreement is here, but not the Checkout form:
https://openairplane.com/agreements
Don't remember if there was an extra charge for the Open Airplane checkout, but I definitely agree the Open Airplane rentals seem to be among the higher priced. I'm not sure if it makes sense for use when traveling if you don't know the area, because you'd still want some local knowledge.