Put a girl through grad school for social work. Her job out of college was snatching babies and bouncing old people in and out of nursing homes. Her perspective was "yeah, Alzheimer's is scary as hell when you're aware that you're losing it all... but the awareness doesn't last. As far as ways to go, it's actually pretty pleasant once you no longer know what's happening." Friend of mine's wife just died of pancreatic cancer. I'll take Alzheimer's over pancreatic cancer any day.
I am currently living with my grandma. She is starting to forget things. She is hates it, she tells me every time that she knows the word and just can't remember it etc. I have read that Alzheimer's is the worst when it starts. People get angry, REALLY angry when they forget things that they thought they would never forget. And then, it just stops. For the people looking from the outside, they are vegetables with a memory span of 5-10 minutes. If I get Alzheimer's, I will be able to rewatch my favorite TV shows as if it's the first time, over and over and over. but only the 20 minute ones, because watching Sherlock will stop making sense after a while.