I am thinking of trading in my 425 for a newer x700 series but am totally confused about all the different models, I am sure there is a difference for all the different numbers in the 700 series but I haven't figured it out yet! One I currently have my eye on is a X740 but really don't know how it compares to the other model numbers or what the differences are. Is there a break down somewhere that shows the differences or do they just come out with new numbers every year? Also wondering about the diesel compared to my old gas 425. Do those of you that have them, like them?