The kitchen sink decision becomes clearer when you bring your largest regularly used pan and admit what actually sits in the sink overnight. One enormous roasting tin used at Thanksgiving should not automatically dictate every Tuesday, but a daily baking tray deserves a vote.
Walk through one normal evening
Do you hand-wash while keeping clean dishes separate, rinse produce while a pan soaks, or load almost everything into the dishwasher? Two bowls can preserve a clear task area. A single bowl can accept a big pot or tray without balancing it across a divider. A removable washing tub can create a temporary second zone in a large bowl, but it must have somewhere to live afterwards.
Single bowl
More uninterrupted space for trays; separate soaking needs a removable tub or different timing.
Two bowls
Independent wet tasks; each bowl has less room for bulky cookware.
Low divider
Some separation with room above the divider; compare useful depth on both sides.
Measure the inside, including the awkward bits
Compare bowl-bottom dimensions as well as the top opening. Sloping walls, rounded corners and a bottom grid can make the usable flat area smaller. Lay out each bowl shape on paper and set the pan on it. Then consider where the faucet reaches, whether the spray hose reaches both corners and where you will set a dripping dish.
The Kohler sink installation drawings distinguish overall sink size from the required cutout. Bowl count alone therefore cannot tell you whether a replacement will fit. Treat the existing countertop opening as a separate approval, particularly when changing from two drains to one.
The bowls occupy storage below as well
A double bowl brings two bowl bodies and drain connections into the cabinet. A large single bowl may still be deep enough to consume the space you hoped to use for bins. Sketch the proposed drains, trap, shutoffs and faucet hose path before choosing an under-sink organizer. A good-looking bin arrangement that blocks a shutoff is an expensive nuisance.
Choose for the task you repeat, not the claim on the box
If hand-washing and rinsing happen together every day, separation may be worth more than uninterrupted width. If you bake, fill stockpots or wash broad trays frequently, the larger single opening may be more useful. Compare cleaning the corners and divider too. The correct choice is the one that leaves fewer dishes perched in the wrong place, with a drain and cabinet arrangement that can actually be installed.
If a compact machine will handle most daily dishes, check countertop dishwasher fit and faucet compatibility before choosing how much sink and draining space you need.