Most of my machines come to me instead of going to the dump.. its how i started restoration. Once fixed up i either keep em for a bit or move them on. Some ive had for almost 10 years or so, but none of them are absolute keepers.. there is always something on the wish list and thats always changing, so i move one on to gain another, or i just make more room.
So no - most of mine are unsighted and unplayed by myself before i buy, but very few i keep for too long.

Pins i want are a balance of artwork and game play.. also "feel"... i have  a few woodrails.. can honestly say that im not old enough to have played these when they were sited... but i know what i want... i dont need to have played them previously.
Then again.... learn to read a playfield layout .. youd be 80% correct as to whether its a good player or not