Whats wearing out on feather sheets that fastIJ Are they comeing out of place bending them and you are calling that wore outIJ I think I noted in earlier post that front wear area of feather sheats on 500 heads have a wear area which could likely be done to a 800 if that is where your wear is taking place. 1000 acres is unbelievable but I suppose there are abrasive dusts ect out there that could!! Maybe smoothing or tapering the contact part of hold down will prevent wear if that is where you are having problem. Be sure cutter bar stabilizer is preventing bar from moving left and right. Sometimes you have to go outside normal channels to make a machine last or work the way you want in crop and condition you are in. I do believe your complaint with feeding would be in short crop or wet crop. I wouldn't want to sacrifice the great capacitiy of 800 head in heavy crop. I don't think the size of auger tube or depth of flighting is giving any problem but more so the distance from cutter bar to auger flighting. That distance should be the same on a 500 head to the 800 head however the 300 head was further ahead thus likely more problems. I think decreasing that distance would help for short crop and hurt in tall crop. I'd think you can make the 800 work in the conditions you were in plus about any other condition by following one or more of the tips discussed lately. 3"tube and or, Gleaner hump and or, HCC level 2 reel and or, reel bats and or, panel that recipricates with sickle (hard to do on a flex)and or, cut back 7" flighting at ends to allow reel to be moved back another inch or two and or, air assisted reel. Usually these 800 heads will work wonderfully right out of the box but if not then adapt them a bit and enjoy.