I have been using during this Christmas period the back door HP 19bii. I had left it on my desk at home, and it was at hand when working from home.
As you all know, the main problem with the Charlemagne Clamshell HP calculators is that they fail always in the same weak spot: the battery door. The batteries make pressure to the door and, with the plastic getting brittle with the passing of years, it will eventually break. The cure is not easy, and never beautiful. It surprises me that this calculator model has never failed in my experience by the hinge that keeps together both parts of the clamshell - all moving parts are prone to fail. Nevertheless, a failure there is not so critical. Unless you program with the solver, you can live with just the right part of the calculator (someone could argue that the HP17bii is just the right part of the hp19bii!)
Sometime ago I found in a shop a Hp19bii that was not boxed, like the original ones, but in a blister, like the new ones. This packaging looked cheap, but within there was a calculator where the main problem had been solved: the battery door had been moved from the side to the back!
That wasn’t the only change. The plastic seems to be softer than the original one; the color is also more black than brown. The keys are alright. Screen contrast is like all old hp19 and hp17 - quite bad for current standards. Comparing a new 17bii+ with an old one is a joke when it comes to contrast.
If you’re used to the hp17bii, then you know how good its menu system is. They wanted to test a new menu model in the hp30b, but it wasn’t nearly as good. And if you’re used to the hp17bii solver, then you also have it there.
Common with the hp17bii is the fact that once you are at a menu level, you remain there until you press exit. You don’t need to start the whole menu excavating process for each new repeated calculation.
But the screen is so much better with three lines in sight (compared with the one in the hp17bii - and a much better font.
You need to factor in several other details:
You can find such Hp19b version (together with an English manual) here