We've been using the same filter in the canister of our central vac for the past two years, as they no longer make filters for our model. The canister also cannot be removed from the wall for emptying anymore, so cleaning it out involves removing the filter very cautiously, shaking the dust off it, and then reaching into the canister with your hand to remove all the crap you vacuumed up last time.
This is the only central vacuum that I have any experience with, it having come with the house, and I have never liked it. There is only one outlet for the hose and consequently that hose does not reach all the way into the upstairs en-suite bathroom. Which, stupidly, happens to be carpeted. Plus, when vacuuming carpets, you have to stop every five passes and pick all the hair/dust off the vacuum head and feed it into the hose manually because the vacuum cleaner doesn't have adequate suction to pick up hair by itself. I guess it's no wonder it takes two hours to vacuum the house.
Losingest. Vacuum cleaner. Ever.
We tried buying a small vacuum cleaner a few years ago, but the motor burned out. Evidently vacuum cleaners hate us as much as we hate them.
I cannot wait to rip out these nasty gross carpets and replace them with something that is not carpet. I don't care what. I would prefer dirt floors, to be honest.
Do you have an appliance that continually defeats you?