Thanks everyone. I was using M101 on a polishing pad with the expectation being to only eliminate light swirls and greatly improve the harsher marring but it was wiping out all marring in my test spot and left the surface looking really good for such a heavy compound. My original assumption was that filling HAD to be occurring somehow. But, that was about a week ago and the marring is still gone and the paint still looks great even though I haven't moved on to my lighter polish. Also, while using two days ago, I noticed a section with marring worse than my test spot so I went over it. When it almost cleaned up the marring but did not remove it, I felt pretty confident it was not filling.
I am really liking 101. I am almost glad a friend I lent my 105 to ruined the product some how and forced me to give the 101 a try. Not sure how my friend ruined the 105 but when you look in the bottle, it looks like a white blob floating in whole milk. He says he didn't leave it in the sun but, he did something. Oh well, the better performance of 101 more than makes up for the loss of 105. People tell me I should try M100 but I am not sure what M100 would do that I could not do with M101 on a lighter pad?