The advantage of EFI is that you don't have to re-jet for large changes in elevation. As far as automatic vs. manual, the only time you'll notice a difference is when you're dealing with large amounts of weight, i.e. a 1500lb trailer. For ease of use, an auto is what you want for running around, and you could do simple tasks like plowing snow with an automatic without any problem. The automatic in the Honda Rubicon doesn't run on the belts like most automatics, so it could probably do everything you want it to do without issue. And unless you're hauling around a lot of weight every day, the standard CVT (continuously variable transmission) automatic transmission that all of the other manufactures' machines have should be just fine for you. Again, the only time you'd definately want to buy a manual instead of an automatic is if you were planning on frequently carrying a lot of weight like a trailer loaded with irrigation pipe, large tanks of spray, ect. For what you plan on doing, an automatic will be fine.