Quoted from rotordave:

Some good points here ...
I have over 100 pins at the moment. Was 113 last time I counted them.
All of them are 1987 (Sys11) or newer. No love for EMs sorry
I have 60 set up and running in my house and 5 in my apartment.
The rest are in my warehouse waiting for restoration. Batteries out of course! And there are some double ups which I am "distributing" through the pinball community.
As CaptainNeo said, when you have a large collection, a lot of them do go unplayed for a long time which isn't ideal. The only time all of them get turned on together is when I hold a Comp at my place ... Which I haven't done for over a year at my house for one reason or another.
Maintenance also becomes an issue, especially if you are working all the time. Trying to keep them all running is a big mission (PHOF style ...)
I have a IFPA Comp coming up at my place in March, we will have Australians and New Zealanders attending, so it will be a busy few months preparing all the machines for the 50-60 people who will show up. Good times!
Dave