Silicone has become one of the new kitchen materials in the last few years. The change to silicone from non-stick coatings, plastic and other materials was made for several reasons.
In ice cube trays, silicone is being used because, while it's flexible like rubber, it lasts longer and stands up to extremes of temperature much better. It's also not prone to staining and absorbing the odor, taste and color of liquids like rubber or plastic would be. So if you want to make drinks with cherry or grape juice ice trays, the clean-up would be easy if you used a silicone ice cube tray.
Another plus for silicone is that whatever you're buying can be made in bright colors. So if you have a certain décor for, say, your wet bar, you are more likely to find an ice cube tray color that will fit into that color scheme.
An important reason for the change is health-related. With several toxins being found in some plastics, people have become very wary, and want to know what the hazards are of using that material. Silicone has been independently tested in several countries, and it has been deemed basically inert, which means it doesn't leach toxins into food the way some other non-stick and plastic items do. (Links to hubs about baking uses for silicone are at the bottom of this hub.)
Silicone ice trays are easy to use, because they're flexible, and the ice can be removed by twisting the tray between two hands, just as you do with plastic ice cube trays. Whether you like small or large ice cubes, your choices will be easy, because several sizes are available. They usually cost between $8.00 and $20.00, depending on how many are offered, what size they are and where they're sold. While you can use ice cubes in any size that strikes your fancy, different-sized cubes do have different suggested uses.
Small cubes take less time to freeze, break down easier in a blender when making smoothies, and cool drinks more quickly. As cooling the drink more quickly means the ice cube also adds water to the drink sooner than larger cubes, this sized cube works best for drinks that will be consumed within 30 minutes or so.
Larger-sized cubes are better for sustained cooling. The larger the cube is, the longer it takes to cool a drink, because it melts much slower than the small cubes. However, that also means it adds water to the drink at a slower rate and lasts much longer. That combination makes it perfect for icing good sipping drinks, like an iced tea in the afternoon or a nice scotch in the evening. (Larger cubes also look neat in a glass.)
With the extra-large cubes, be sure that you know the cube can make it to the bottom of the glass. You don't want cubes getting stuck part way down the glass.