I normally use
Fuzion, or other carnauba's over Wet Diamond. I like the looks, but it does take some of the slickness of WD away though.
I had Wet Diamond on my car by itself when a bird decided to crap on my hood. It wasn't on very long, but it ended up etching the paint.
Since then I've been using a carnauba over any sealant I have to hopefully help if another bird bombs my car.
Fuzion is a good wax, but I wouldn't spend $175 for it. They had a BOGO on the 3oz tubs not long ago. May still have it going on.. Not sure. The 3oz will last you a long time.