My mother always said keep things that make you feel good, don't keep anything out of a sense of duty or because you feel guilty getting rid of it.
Some may think me strange but I believe things carry "karma","feels" (whatever you want to call it) with them, I don't think I've ever seen them as "just" objects...coffee tastes sweeter in the right cup, but some cups, no matter how nice will always make lousy coffee.
If my memories are good ones, if it makes me feel good...I use it, enjoy it, and keep it for as long as it does. Otherwise I find another caretaker for it...in worse case situations with things that hold memories of illness, grief, stress, or hatred...nothing beats a good cleansing by fire.