[VLM]

My HP-48sx is 21 years old and I still use it roughly daily at home.

I have an emulator on my phone but the tactile response of the keys is awful and the display and keyboard are tiny compared to the "real" thing.

Its just too easy to use. Latency of the calc on my phone is very high compared to a fraction of a second. If my desktop is up and running and logged in and a webbrowser is running (lots of ifs) then google and wolfram alpha are starting to eat into the 48's territory. But it still gets plenty of use. Batteries last about a year.

I also have a 32Sii at the workbench vaguely 90s vintage.

[epo]

Still using a HP-16C (the computer scientist) bought in the mid 80s, the first set of batteries lasted about 10 years.

[jonsen]

My first set lasted longer. Still on second set.

[WalterBright]

I sold mine recently on ebay. 30 year old original battery still worked! I think it found a nice home with a collector.