I purchased this Kohler valve body to go with a 3 handle set for the bath/shower in my home. I like the quality of this product; I had looked at several other 3 valve units at my local stores and found tapped threads with large metal shavings still attached, etc. The Kohler part was machined better with more attention to detail - no burrs, etc on the unit. That says a lot.
The ceramic washer system is wonderful, as is the 1/4 turn feature for full off to on. I had the old gerber style system with rubber washers. I had to replace those every few months to a year and I was still getting drips. Plus, when you turned them, you didn't get a smooth change in flow rate. The Kohler unit is flawless - no drips, and it smoothly changes the flow from off to on through the 90 degrees.
The holes through the wall needed to be enlarged for the valve body - the old gerber valve body was considerably smaller.
That said, the only disappointment is that the valve bodies must not be quite the same between manufacturers for easy replacement. The 8" width is right, but the vertical distance from the valve body centerline to where each of the 4 connections is made isn't the same as the previous model. I had to alter the plumbing length for all 4 connections, which turned this job into something considerable longer. This is something these manufacturers should have standardized a long time ago.
UPDATE: After one week of use, the hot water valve cartridge failed (water flow would not shut off). Later found out a small screw was in the valve and caused it to fail. I can't figure out how a screw ended up there, and cannot tell if it came from the factory or it was me. Lesson - check the valve body for foreign materials just in case.