Dave:
Maybe you have answered your own question: The positives you`ve mentioned do not outweigh the negatives. That and the fact that their new Mirror Glaze M110 Ultra-Pro Compound is available for about the same price, so you do have some "internal" competition on similar products from the same manufacturer. Just guessing.
I do know that D301 Finishing Polish and Wax has gotten some good comments about it for an All-In-One product, even though it may not be intended as that.
Megs has so many product lines (Consumer Gold Class, Consumer Ultimate, Consumer Hybrid/Ceramic , Pro Mirror Glaze, Pro Detailer, Mirror Glaze Marine) and products that cross over into one another, it is sometimes difficult to keep them straight.
That said, many of my detailing products are Meg`s because:
1) It`s readily available, even over-the-counter
2) They are relatively inexpensive or very cost-competitive compared to other car-care manufacturers
3) They produce the results I like
4) They have been around for a long time and their customer service about using their products is excellent
Are they cutting edge with new car-care technologies? No, not since the merger with 3M. There is a lot of car-care product competition these days, and with the advent of forums like this and internet sales of those various products from multiple manufacturers, hobbyists and professional detailers have more to choose from, which is good for us Autopians.