This is what the rep from Meguiars said to me in the seminar I attended last night. Let you know I am only speaking in terms of Meguiars QD only and not comparing it to others.
The Mirror Glaze Line "Final Inspection" (M-34) is said to contain no silicons at all. It is acrylic based. The down side to the use is hot weather. It will tend to streak like crazy on Black in the sun. The second product Detailer's Line "Final Detail" is said to contain some carnuba wax. It does very well in the hot sun and will not streak.
This is what the rep from Irvine Corp. said.
Bottom line is to try a few lines and see what you like the best. I personally like Egale One or Mothers for my black car.