Quite a few years back, before my exposure to HP calculators, I've used a Casio FX-850P, which I found, then, to be a great calculator; mostly because of its integrated basic (which, truth being said, not outstanding, but still great for a 12 years old).
As one might expect, I used it for just about anything, as an organizer, databank, and, of course, portable computer (even had a few games on it). I liked the horizontal keyboard, which was very usable, along with its formatting (qwerty); that was a big plus.
I was wondering which HP calculator would be closest to the FX-850P, I seem to believe it would be the HP-71b, but I could be wrong on this. Maybe the HP-200lx (I don't want to raise flames here, I know this is mostly a RPL forum). Today, I do mostly everything on either my 48gx or 50g (migrating to the 50g because of failing memory cards on the 48gx).
One of the obvious disadvantage I could foresee with the 71b would be its 1-line display, but again, because I never had exposure to this, I wouldn't know; hence I ask.