What's your favorite non-RPN HP?

[John R]

I'd have to go with the 27S. It's kind of like a less talented baby brother to the 42S, but one that still shows a family resemblance with some of the same traits.

One nice feature that makes the algebraic logic on the 27S slightly more palatable than that of other algebraics is the continued display of pending operations -- it's not as nice as RPN, but still a big step beyond models that lack any notification of pending operations, and a nice improvement beyond the other HP algebraics with their "PEND" annunciators.