Autoglym stuff is generally "ok". Some of their products are good for ease of use/all rounders, others are just bottom end of the market.

The only reason Autoglym stuff is so widely used is because it's stocked in all kinds of shops all over the place, so that's what Joe Average sees the most, whereas the better, more specialised stuff is only available online and only really known to enthusiasts.

Some Meguiars stuff is excellent, I've got loads myself, but the kit mentioned above is rubbish. Branded for convenience/ease of use.