The only negatives I've heard about are the 1.25" aluminum tool arms and the incredibly high price for the machine.
I've worked on this grinder, and have to agree with the above statement. While there is no doubt it's "top quality" throughout, using a 1 1/4" aluminum tooling arm is a major design flaw in my opinion. I also agree that the platen is somewhat "over engineered". To achieve the same flexibility as my current platen, I would have to basically trash the platen it comes with, and replace it with one of mine.
I once watched as one owner accidentally dropped a tooling arm with an attachment in place, and it slightly bent the tooling arm...causing major tracking issues. I also noticed that the aluminum tooling arm gets "chewed up" rather quickly where the "hold down" clamps it in place.
I personally wasn't happy with the height difference between the vertical and horizontal positions....I suppose to some that wouldn't make any difference, but for me it did.
If the machine came with a steel tooling arm(s) (preferably 1 1/2") and the vertical and horizontal heights were the same, I might seriously consider the machine for my shop. But as it is, giving up the horizontal feature, I think a KMG is a better value.
I'm not at all dogging the grinder.....there are just some things about it that are "deal breakers" for me. All of the folks I know who own them are very fond of them....but there are just too many short comings for me, to spend that much money on a machine that I would have to do a lot of modification on, to make it fit my needs.