Product review (5 stars): The One-Cube Size Model of Three Offerred
I received a free item to review.

Three of them, actually (they make great gifts for people without refrigerator built-ins, or who entertain a lot).

The difference between the three models of Ivation portable mini-icemaker comes down to the number of ice cube sizes each can produce (1, 2, or 3), the relative size of the compartment lid, the control panel and its orientation (top or front-facing), and the overall size/style of the unit.
The compressor, capacity, and operation of the three models are essentially the same.

 I went into more detail in my review of the 3-sizes-of-cubes model so Im just going to recap here:

This particular model produces only one size of ice cube. My fridge built-in only makes one-size and I've never thought it a problem. The size corresponds to the 'large' size of the two-size model and the 'medium' size of the three-size model.

The ice cubes are shaped like hollowed-out rounded cones, not the semi-circular solids many refrigerator built-ins produce nor the classic cube shape you get with freezer trays.

It takes just over a 6-cup Brita pitcher-full of water to fill the icemaker to the max indicator. The compartment lid stays open by itself so pouring is comfortable.

It takes about two hours to make cubes using just about all of the water. All three units will simply detect and go into standby when the basket is full so theres no worry about overflow. I emptied the basket twice, the first time at about the one hour mark.

All three icemaker models are very easy to operate and don't produce excessive noise. The three-cube model has a somewhat more complex control panel with a standby/pause function and auto on/off timer. It also provides a bit more feedback in the form of troubleshooting icons.

This one-sized cube models is probably the simplest to operate and I think the appearance of the control panels is more attractive than the one on the three size model.

All three models use the same drain plug mechanism and are easy to position over a sink.

Bottom Line: All three icemaker models are well-made and attractive  although all are too large to keep permanently on our countertop. The hollow cone-shaped cubes are an acquired taste but if you entertain a lot and need to crank out more ice than the fridge can handle (or you don't have a built-in), its a handy and easy-to-use addition.