My grandmother has been in an assisted living facility, first on the independent side, now on the fully-assisted side, since 1994, and she's now 95 years old. It has only been in the last year or so that she's begun to lose her mental faculties, and, unfortunately, now has inoperable bowel cancer.
(we don't know how long she has, but she's been "ready to go" -- as she's told me on numerous occasions -- for years).
Nevertheless, she has absolutely loved the building in which she's been living these past 10 years, even more so since my grandfather died in 1996. She has eaten well, enjoyed countless hours of bridge, majjong (sp?), music performances by local schools, large print books, shopping trips by bus to the malls (she never learned how to drive), etc... I have no doubt in my mind that living in the building extended her life substantially, allowing her to spend time with her two great grandaughters (not to mention the myriad of other family members who live near the building, including my parents).