Funny, I didn't really hear Starwood had an "atrocious" footprint pre-merger...I did 900 nights in 9 years with them, and I can count on one hand the amount of times a property wasn't available to me. But yes, if you are a traveling salesperson and need to be in small towns - Marriott is the program for you!
BTW pretty sure Hyatt, with all the recent acquisitions + SLH tie-up, is now bigger than Starwood pre-merger. I have been pleasantly surprised at the breadth and depth of properties.
It is pretty clear the above-and-beyond Ambassador experiences of a couple on here are the true outliers...the program is a shell of its former self. BTW it is a far inferior status level to Globalist, it's not even close. Compared to Titanium, you get a Your24 program that basically doesn't work anymore, and possibly a dedicated (along with 299 other customers) agent who may get back to you in 48-72 hours if you are lucky.
If Marriott actually wanted to improve Ambassador, Globalist is a good benchmark - no resort fees on any stay, no parking fees on award stays, Guest of Honor benefit, advance confirmable upgrades, full/real breakfast no matter what, add'l benefits/incentives once you hit the top tier...IMO it's shocking how good it is, the more I learn about it. Heck, if Marriott matched ANY single one of them, people in this forum would be hailing Marriott for how elite-friendly they are.