I have only stayed a a few FIs, and gave up on them a few years back. I usually book the suite at the Ctyd prop if I am not staying at a FS Marriott. That being said, I do prefer the consistency of the Ctyd over the FIs. I travel a lot in the soutwest (AZ, NV, & NM) and found the FIs in these areas to be poor in quality. I can speak for Flagstaff, Yuma, Tucson and San Diego, CA. Although I've found a couple Ctyds that I wasn't thrilled with they were generally scheduled for renovation (Las Vegas Green Valley location comes to mind).
As for pts on incidentals I've been getting them as of last week? I won't be listing my account number or the hotel location for Marriott to start their audit on this though!!!