I fell into the Marriott system pre-2000's working in North Carolina, and for years regretted not using other chains. One regret was not working my way up the Sheraton group, but when the merger happened, I could not be happier. Funny (strange) thing was just the merger was happening, they rolled me over to the Sheraton program, my record shows I'm from that side of the group.
Lifetime titanium makes it a no-brainer on where I stay generally; Club, breakfast, early & late check-in, upgrades, etc, saves a lot of money.