I bought some Plastis Ice Cube Trays from Ikea a few months ago to try them as an alternative to Rubbermaid Periwinkle Ice Cube Trays. I have used the Rubbermaid trays for years in the places that my wife and I have lived where the refrigerator didn't have an automatic ice maker.
I want to report that the Ikea ice cube trays are much better than the commodity Rubbermaid product, but it took me a bit of experimentation to realize this.
I decided to try the Ikea ice cube trays because the Rubbermaid trays are made of a harder plastic and are prone to cracking with repeated use. This causes water to leak in between the ice cube forms on each tray. The Ikea Plastis Ice Cube Trays are made of a flexible synthetic rubber that doesn't crack, so I expect to get a lot more freeze cycles out of each one. Both products are dishwasher-safe.
The concern that I had initially with the Ikea Plastis Ice Cube Trays is that I found it difficult and time-consuming to get the ice cubes out of the trays immediately after I removed them from the freezer. The solution to this problem, which is totally undocumented, is to take the Plastis Ice Cube Trays out of the freezer three to five minutes before you try to remove the ice cubes. If you place the trays on the kitchen counter for a few minutes, the ice melts enough to make removal of the cubes really easy.
Plastis Ice Cube Trays are designed to produce a number of unusual ice cube shapes including hearts (shown in the photo), doughnuts, stars, plus signs, arrows, and long bars that look like drink stirrers.