Test Before You Buy
Be careful when making your purchasing decision. Not all composite decking products have the same density and strength. Some products can be easily dented with a hammer or incur damage from objects you might drop. I urge you to buy just one piece of all the products you're thinking of using. Do your own drop tests using common things you might carry on your deck, such as a filled propane container, tools and so forth. Drop them onto your sample pieces and see what happens. Pound the materials with a common hammer.
Cooking grease can be a real issue. If you have a composite deck with exposed wood fibers, the grease can soak into the wood fibers. Use an oxygen bleach and warm water to get rid of these stains. The oxygen bleach will also remove the gray coloration from any exposed wood fibers if you own a weathered composite deck.