A while back I loaned my elderly (late 70's) father a Glock 19 since all that he had was an old .38 revolver from the 30's and a .22 target revolver from the 60's. Bad idea. After having several recurring nightmares, and watching his hand shake as he held it, I switched it out with a CZ P-01. He told me that he felt a lot more comfortable with the P-01 since he could see the hammer and that it had a "safety of sorts". He also told me that he was scared of the 19 and probably would have picked up his ancient .38 instead. The P-01 is temporary until I can take him to check out and shoot other handguns in the near future.
My father is no stranger to firearms and has been shooting his entire life. He has a butt load of long guns in addition to the two revolvers. I learned that it's not easy selecting the right handgun for an elderly person.