If you are wanting to put a clear coating on your deck, then there are no "good products" in reality. It's not necessarily the fault of the coating but even if you were able to keep the wood dry the effect of UV and hot/cold cycles will age the wood quickly. Deck coatings are one of the hardest hit in terms of weathering that there is, you are asking a lot of whatever you put on it.
If you want to protect your deck the best solution is an iron-oxide pigmented system, of course you lose the wood look. The next best option is a semi-transparent iron-oxide pigmented system. Your clear systems would be last. To maintain a good looking deck with a natural look you are going to have to invest a lot of up keep time to maintain it.
A non-yellowing (solvent) oil-based system will probably give you the best results long term.
