I've kept an old 9100 just for old time sake
how sad is that!!
Not so sad, I've still got one, now in its 3rd hse, 20/30yrs in total?
Has always done what I need & I've got spares of everything if needed, boxed & never used, it's still going strong.
I use it for a little more than a normal alarm. By using the plug on relay board it has been possible to use the relays for isolation of different things when the alarm is set/unset, it's amazing what can be done with a little thought.
Yes I know modern panels would be able to do what I have done plus a lot more, but remember I sorted out all of our needs before to days panels were ever thought of, & they still work, why change?
Never had a F/A in all this time, (& yes it does work, see next) battery is replaced on a regular basis & servicing is a doddle & done regularly.
If it aint broke, don't fix it, is my motto