With the Jayco, everything is 1-2 years old.
With the Tiffin, you will need to investigate how old anything really is. When were the tires last replaced (on a 6 year cycle, they should be due for replacement soon - $3000). Is the fridge, microwave, TVs, water heater, toilet original? If so, they may need to be replaced soon. Has the roof, tranny, and engine been taken care of? Are there records of repairs and maintenance?
If I was at the top of my budget and looking for a bus with the least amount of potential cash outlay for repairs, I would pick the newer coach. Gas coach maintenance is typically cheaper. If I was buying at the middle of my budget and had a nice cushion for repairs, my choice would come down to which was in better condition with a better floor plan.