I tried my glass cooktop cleaner this morning and I think it did a pretty good job. It is called Astonish and I got it on QVC. I think it is made in Great Britain. It took about 2 minutes of rubbing (I just used my finger.) The picture quality is not great, sorry.

The color looks lighter in the after picture, but that is just due to my picture taking skills.
Before
After
Astonish
PS It really does a great job on glass stove tops (best I've found) and also found it to be a great cleaner for my fiberglass shower stall.

Joe