I had 2004 and 2012 V-8. Excels and a 2007 V-10. MPG is about the same, the V10 has more power, an extra gear in the transmission, I believe the 07 is a 4-speed overdrive and the V-8 was a 3 speed overdrive, you will have a much greater towing capacity with the V-10, and Lower rpm at highway speeds. They are also much better climbing mountain area roads. Price wise I think they are both too high, but they are hard to find. Finally the Excels are great units with minimal problems, well constructed Pleasure-way quality.
Good luck with your choice.