My sink has a rim. Why is Pete’s Sink Mount kit better than attaching the rim to the countertop?

Rimmed sinks are typically attached to the countertop using three methods.   All methods use the rim to “hang” the sink in position.   Supporting the sink from the bottom is a far more robust and sturdy solution while offering much greater flexibility in placement of the sink.

1. Construction Adhesive:   Commonly used for lite weight stainless sinks.   The sink is basically glued to the bottom of the countertop.  The sink will be clamped in place for a few days while the glue dries.  Works for a few years before the weight, vibration and moisture causes the adhesive to fail, usually when filled with water and dirty dishes.
2. Clips: Used to attach the sink rim to the countertop by notching the countertop material.   Some countertop material, such as granite, is very brittle and will eventually chip and break.   The notches are not very deep into the countertop material so there is minimal strength holding the fasteners/clips to the countertop while weight is continually pulling down on the slips.  Any notching of the countertop also makes weak spots in the countertop.
3. Rails and Screws:  require notching the top of the cabinet to install rail pieces which have screws that are used to push up on the rim so the rim makes contact with the countertop.  Rails cannot be removed without removing the countertop.