Mine works good so far but only 8-10 hours on it. Mostly wide open after breaking in !!! SLP Piped with airbox mods and autotune c/w PC-5 and still need to work on maps- still running a bit lean ~13.4:1 with supplied SLP map at nearly wide open throttle positions. Need to be careful !! No snow to go hard but maybe next week. Latest '09 or early '10 updates burned into Polaris ECM. Put on some EGT's now too and will watch it closely for next little while; piston wash and plugs etc. Seems to run real good though !! Pulls to ~8100 rpm nearly all the time with 68g and maybe some clutching will still help. Dyno perhaps soon too if I can find someone decent to find out where the powerband is. Cost me a pile of cash to after a SEVERE blown motor at very low km and just off 2 yr engine warranty. Polaris gave up but the aftermarket seems to have figured it out. No immediate thanks from me to the OEM as they walked away from many customers .......... but the dealer who helped out I thanked them for some good service and pricing on some pieces that were MELTED/BROKEN/JUNK !!!