Product review (5 stars): Excellent -- You DEFINITELY Want This Kit.  Really.
Highly recommended.  Just buy this.  Do not even THINK about buying the original model.  This IS an official replacement part, and it is a substantial upgrade.

Yay!  I've been soooo frustrated with the original Kitchenaid parts.  After replacing them 18 months ago, I had 3 wheels broken.

This kit was a perfect replacement.  I installed the first side carefully, watching the (sorter of the two) YouTube video step-by-step through the process. The video isn't great, but it definitely provides enough information to get the job done.  Going back and forth from video to rack, I installed the first side in about 5 minutes.

Having done the first side, the second side took -- no joke -- less than a minute, including the time needed to screw-in the screws.

The kit does come with a little bitty Torx adapter in the parts bag (right from Whirlpool)... So if you want to save yourself a couple of bucks, you don't need to buy the Torx screwdriver.

My wife thinks I'm a kitchen handyman hero for installing this upgrade kit.  Awesome.