In a past posting (3/31/2010), I discussed the basic categories of synthetic decking. Those are the composites (wood and plastic fibers blended), solid cell PVS (basically all plastic), and the recent Plastic wrapped around a composite core called Cap Stock. Some of the top companies have produced some very attractive new plastic deckings that even as a “wood guy”, I am impressed with the look of these products.
These new plastics are the latest developements in the evolution of synthetic decking and I believe them to be superior in overall performance in regards to fading and other appearance degradation and they are easier to keep clean as well. I also find the the plastic deckings offered by Fiberon (Outdoor Flooring), Azek (Procell) and Timber Tech (XLM) to not be slippery. They are offered in the exotic colors, mimicking woods such as Ipe, Rosewood and Teak. 
Fiberon, and Timber Tech offer a full line of synthetic decking composites, cap stock and solid PVC. To the right is a Fiberon “Ipe” cap stock.
Azek offers a variety of solid plastics from the basic colors such as gray and beige called Brownstone to exotic colors named Morado, Redland Rose and Acacia, the dark brown seen to the left.

In terms of quality, mold reisistance, fading, and surface scratching which do you think is better the Azek Collection, Fiberon Horizon, or the Best Grain Classic collection
Antinino- I am not familiar with “Best Grain Classic”. Azek is a solid cell PVC all through and the Fiberon is plastic on the exterior around a composite core, so both are plastic to the weather. We have installed both products and have been pleased with the results, so far. I say so far because neither of these products have been on the market for long term. We have more experience with Azek (about 5 years) than Fiberon Horizon ( 2 years). Both Companies are good companies and I believe they will stand behind their products. I suggest you find the color and price point that suits you best and go for it. Thanks for reading. Rick