My 6500LP is still happy at 27 years. Had to replace the regulator a couple of years ago.
I have a motorhome that came with a huge propane tank so I'm not as restricted as I would be with small portable tanks plus I only run it on travel days. I don't boondock other than at repair shops when something breaks (13 days at a transmission shop) so fuel usage isn't really a problem although propane can be hard to find sometimes. Also I very rarely run the propane-guzzling furnace.
It really depends on your intended usage. If you forsee a lot of boondocking depending on a generator, propane isn't for you simply because it's lots easier to transfer gas or diesel into a day tank as often as needed. If you forsee boondocking with lots of solar etc, no air conditioner, and generator usage would only be for the occasional rainy day then it'll be fine.
