I got one recently. The 'mix screw' is also kinda misleading ----- it still has a jet that needs to be tuned to your set up. The screw lets you do a finer adjustment than would be allowed with just a jet change. Mine came with a #58 jet and is still too rich for my bike. WIth that being said, when I took it to New Mexico (9000ft elevation), it ran the best it ever has up there.
Haven't decided if I'm gonna get a few smaller jets or find a precision drill bit set so I can make my own jets........