I am picking up a used 2001 ZL 500 efi esr with low miles. I don't really care to spend $7000 on a new sled, but want to upgrade to sleds with reverse and electric start. I also like the efi. I am interested in any experience people have had with this sled and the non valved 500 efi engine. HP, speed, and fuel mileage are concerns. And do the APV engines provide an increase in mileage that offsets the $30/gal oil cost.