Lazy susans look identical and vary enormously in how they behave once loaded, and the difference is in a component you cannot see.
Two Ways of Spinning
The cheap approach is a moulded plastic hub rotating on a plastic base. It spins freely when empty and gets progressively harder as weight goes on, because plastic on plastic has real friction.
The better approach is a ball bearing race between the two plates. Steel or nylon balls carry the load and roll rather than slide, so the spin is almost unaffected by what is on it.
Loaded with heavy jars, the difference is obvious immediately.
What to Check
- Whether ball bearings are stated rather than smooth-glide adjectives
- How it feels loaded, not empty, if you can try one
- Whether the base is wide enough to be stable under load
- Whether there is any wobble when pressed at the edge
- Weight capacity, where it is given
Where a listing names the mechanism, of the kind stated on some models at https://copco-usa.com/, that is the specification worth reading. Where it does not, assume the simpler construction.
Why It Matters More Than It Sounds
A turntable that is hard to spin when full is a turntable that does not get spun.
People reach past things instead, which returns the cabinet to the state the turntable was bought to fix. The mechanism is what determines whether the habit forms.
The Rim
A raised outer edge stops items sliding off during rotation, and it is more important than it appears.
Without one, tall bottles walk outward as the tray turns and fall off the edge. With one, the same load stays put.
The trade is that a rim makes it slightly harder to lift items straight out.
The Non-Skid Surface
A liner or textured surface that grips the base of whatever is standing on it.
It stops bottles sliding while the tray accelerates, which is the other way things fall off. A smooth plastic surface with tall items on it behaves badly.
Level Matters
A turntable on a shelf that slopes will drift back to one position on its own.
Cabinet shelves are frequently not level, and it is worth checking rather than blaming the turntable.
Clean the Race
Crumbs and sticky spills work into the bearing and stop it turning. Wiping underneath occasionally is what keeps it smooth.
Try It Loaded
An empty one tells you nothing.