Cuisinart Ice-20 vs Ice-21

These 2 are great ice cream makers, the ICE-21 is the newer version of the ICE-20, but they have the same features. They are almost the same except for some tiny design differences.
As you can see from the product images: the lid, location of the On/Off switch and logo, and the base shape.
For the inner part that you cannot see, the mixing arm is slightly different, information online said that the new mixing arm design on ice-21 makes the processing time shorter by 25%.

The freezer bowls on ICE-21 and ICE-20 are interchangeable, max capacity is 1.5 quarts.

Both carries a 3-year limited warranty.

Some reviewers of the ICE-20 complained that the consistency of soft serve was too soft, but some users said that they had no issue with the ice-20.

All in all, the small difference is not a big deal, both are excellent and easy to use, just choose the color you like. For example, ICE-21 is white, ICE-21WM is in Watermelon color, ICE-21R is red, ICE-21TQ is Turquoise; ICE-20 is white, ICE-20R is red, etc. Unit is the same, only the color is different.
(Cuisinart ice-20fr is Factory-Reconditioned, Cuisinart ice-20a is sold in Australia.)

By the way, the ice-20 is discontinued. So, buying the ice-21 should be better.

The official links:
https://www.cuisinart.com/discontinued/ice_cream/ice-20.html
http://www.cuisinart.com/products/ice_cream/ice-21.html

ice-21 video:

ice-20 video