We have between 8500 and 10,000 acres on our 2000 model.

Replaced all the bearings holding the poly sprockets on last year (half of them were out when we did the post harvest check over).   Still on the same gathering chains, rollers, and deck plates.   Purchased a new deck plate last year and it looked like the ones we had, so it was returned.  

Parts like anything is dependent on your dealer.  Here in Wc/Sw Mn we are blessed.  Ours has poly, for some odd reason they haven't had narrow row poly (less than 30").

It chopps better than the new CaseIh heads (new holland), but not as good as the old Case heads.

Its been a good head.