Good day all! I am new here to the forum, but not new to wheeling. Currently have a 2000 Sportsman 500 RSE (LOVE it!) and am looking to pick up 2 new ones for the wife and I. We don't do any speed runs nor live in the mud. We do like riding trails and the occasional trip through some muddy stuff. I am leaning towards the 550 and the 570 for us both. My 500 (not H.O.) has more power than I have ever needed and will go plenty fast for me. That being said, I am curious of the difference between the 550 and the 570 EFI. I would imagine the 570 will be somewhat more efficient with fuel being EFI, but why the price difference? What are the big items to sway a purchase one way or the other? Thanks in advance!