Here in Oregon, we pay a premium price for what you pay back east; i forked out 2300 for a 5' KK tiller. Recently, Prefert is selling at the same farm store I bought my KK at. A 5 foot Prefert sells for about 1800. It has heaver steel in the sheet metal than the KK so less likely to dent and crack the paint. the gear box and tines look about the same. If I had to do it over again i would gamble on the prefert.
After looking at the prefert, I am removing the sheet metal on the KK and having steel re-bent and welded into place that should make it look nice as the sheetmetal is cracking loose because of the vibrations...