Hi, Jim, Nigel,
I have very few details on the "big runner" of the 2 calculators.
I have some more info on the 10.000 uds. model, but I still don't have a protoype in my hands to give an informed opinion.
The blog just shows my personal preferences (with my limited knowledge). I do think that the HP 50g is a substantial improvement over the HP48g family in screen, speed, and software. Not better in keyboard quality, but not bad either. I do think as well that the colour scheme is better than on the 48g/gx (not than 48sx).
As for the 15c, it is a little lovely calculator. It does everything I need on a daily basis, and I can program it with my eyes closed. I like the HP42s and I can admit that is a better overall calculator, but I don't "love" it.
Yesterday I had a nice surprise with the 30b. Good all-rounder for business, and good keyboard. Extremely fast. There is future!