Some questions regarding the "HP12C+" model

[MountainMantologist]

Hi everyone - brand new to the forums!

I have a handful of vintage made in the USA HP12Cs that I use on a daily basis both at home and at work. I love their build quality but I wanted something faster for longer amortization calculations where the original takes quite a while.

I learned about the model colloquially known as the HP12C+ on these boards and just ordered two of them off eBay. Or at least I hope I did. I now realize I should've come here for answers before purchasing anything!

My understanding is that all of the gold HP12Cs with the dual-CR2032 batteries are the faster models with the ARM processor. Is this the case?

And, if so, do we know what years they made this model? When I go to the "HP12C English" page on the HP website the tech specs indicate they take a single CR2032 battery. Does this mean the 12C+ was a limited run from 2009ish(?) to ____? And does that mean the brand new calculators you can buy today are slower than the older ones with the dual batteries?

Thanks in advance!