We often see posts on this site suggesting that Marriott is terrible because of one bad experience.
The real questions should be "What's the worst that happened? How often does something bad Happen? And What did Marriott do about it?"
We should also post the same questions about the competition!
I'll start off my own thread with my own horror stories.
At a Fairfield Inn in southern VA (about 6 years ago) we checked in and when my wife looked at the sheets they were obviously used and disgusting. It turned out that the maid and her boyfriend had used the bed after she had made it. The hotel gave us a new room, the manager moved our luggage and comped us and gave us extra points. I never had another experience this bad.
We stayed several nights at a Hilton in England about 10 years ago and then were told (at checkout) that we did not qualify for points because our membership was US and not UK. (We had booked our room through Hilton's 800 number.) No compensation or apology was given and we were told that it was our mistake to expect points. I used up my remaining Hilton points and have not stayed at a Hilton hotel since then!
About 20 years ago a Best Western shut down the breakfast room about 45 minutes early. We felt that our breakfast at a nearby Waffle House should be paid for by Best Western but Best Western refused to do anything, other than ask the hotel to help us, because be had not booked the room through their central booking. The hotel did nothing for us. I've stayed 1 night at a BW since then out of more than 800 nights in hotels.
Marriott made good on their errors and we give Marriott our loyalty. I expect problems to arise occasionally, but I expect them to be corrected or I expect apologies and/or compensation.
I mentioned in a prior post I was going to stay at a Sheraton outside Boston and we got snowed in and I called but phones weren't working but left a message . Showed up the following Saturday and were told no reservation and we were charged for no show. of course I explained and they could care less. I wrote to corporate customer service and never got a reply. So no show was 140 dollars twenty years ago . Since then I bet I have stayed 1500 nights in hotels and only one night at a Sheraton