Great question! I have 95% cut ties. I'm quite enjoying Hyatt so far - competent, dare I say good customer service, IT that actually works, nice property base...very SPG-like. Globalist benefits (will be there in a couple months) seem amazing.
WRT Marriott, I have a couple of "nice stays" this week (then basically done, save for burning off points), and I am SMH at the state of the Ambassador service these days. Gary summed it up nicely.
Objectively, it's just embarrassing how poor/unresponsive the CS is, for supposed top tier, high value guests. I can only imagine the frustration low/no-status folks are feeling with Marriott.