Hello, I have started shopping for a Hi-Lo, and I see lots of different models out there. Why is it that some 17-footers have dual axles and some have just single? Are there pros and cons to one or the other (other than the obvious of only having to maintain two rather than four tires)? I also have to think about ground clearance because of the dirt-road places I go, so any advice on certain models/years for better clearance and durability would be appreciated. Thank you very much for any advice you could lend!