Thanks: Perhaps I shouldn't have used "brand name" vs "generic". The upshot of this seems to be that you can't go on the basis of "brand" very well. Penetration of the market by different outfits seems to be geographical. Also, as CCI points out a "brand" name (Deere, etc) are not necessarily better.
If I am reading the thrust of the responses accurately, you have to look at the specific items and how they're made. The problem, of course, is you don't know what they're made from. As JimMc points out, some stuff that may look the same is better quality, ie. Italian tines vs Indian tines. By the way, the Italians seem to have greatly improved their manufacturing quality from previous years - remember the old Fiats that had hair growing out under the wheel wells? (just kidding). Anyway, they produce some first class garden tractors as well as larger stuff.
Some brands mentioned are "brand" names around here too (King Kutter, Bush Hog) while others I have never heard of (Leinbach) even though they may be very good stuff. So . . . guess I will have to look/see on an individual basis to figure out the best to get. Wish the manufacturers would "tell all" as far as where the metal comes from (its not that hard to evaluate construction quality, but much harder to figure out material quality - which is why my original question - you are relying on the manufacturer's metallergy dept if they have one to select the best metal). And, of course, some very good manufacturers wholesale to other brands. Was looking at a King Kutter 72" tiller the other day (only $1.2k) which looked very solid (geared drive, slip clutch, etc) and I'll swear it looks exactly like a Woods medium duty tiller. Same unit??
Anyway, thanks. JEH