Ron,

Yes I have the adapter, it fits very snugly. I've used an older webcam with a Delrin machined adapter (the AgenaAstro ones are aluminum) and after a while it started to wear and need to be replaced.

I also use a UV/IR 1.25" filter, mine is the Celestron model (which I believe is made by Baader). Without the filter I notice a bit of softness on the edges of a planet and I think I get a bit more contrast on Jupiter and Saturn's belts.