Well to be honest, there really isnt much of a comparison...the Z400 is a great bike, handles great, good power, and tons of after market parts. However, you do need to dump some $$ into suspension and engine to get it up to par with the YFZ. Same thing goes for the raptor. The raptor is heavier, tippy, and has good power but its not YFZ power. As far as reliabilty, well the rappy had the tranny problems, starter problems. The Z had frames and axles. The YFZ so far has had 2 cases of bent lower arms.