Howdy,
I am still using my 340 from 2004

Still kicks ass and I won't part with it for anything. I have only had to change the battery two times.
I want to move to microSD cards shortly now that sufficient support exists with hardware to do this easily.
Did you manage to find an upper limit on capacity of cards in your testing? I don't want to spring for a 256GB card when it might top out

Thanks.