After three years the first set of discs were down to 18.5-18.75" from 20" I believe. They were still working okay and I could have moved the scrapers up to the higher notch, but changing discs was easier. I felt like the scraper was getting unnecessary wear and they are more expensive than discs. Now after two years in drier conditions I probably will do them again because the bearings are being done and it takes a few seconds when out. They aren't as worn as last time. I have some Ingersoll, CNH, and Bourgault discs on here to compare wear, so that will be interesting to see.
As far as hairpinning I really have no reference point so can't give a comparison to other brands. I do know I can not apply the type of down pressure with a 7.5" as the 10" guys can. So a 10" unit would definitely be better.
For power use I am running in worked ground today and tractor is at 50% at 1500RPM going 6mph. I always go 6mph although I could go faster. I do know doing peas quite a bit deeper and running with a full tank of peas and phosphate I had to drop a gear on the steep hills. I suspect it would be around 75% on the flat ground but I never really paid attention. Slip showing around 2% right now but I can't say that is perfectly calibrated, slippage is not high.
AN ERROR DOESN'T BECOME A MISTAKE UNTIL YOU REFUSE TO CORRECT IT
Orlando A. Battista