We bench-tested a decent amount of the products offered by AutoGlym in our shop and none of them were any good. Actually, the right word to use is 'junk.' You're better off using something that is tried, true, and of high quality like Meguiars. In our opinion here at my store, the AutoGlym is quite over-priced for what it is and it delivers less than stellar results.
In terms of clay bars, we have started using 3M mild and aggressive clay bars over the past year and have found that they perform well and hold up with repeated use.