John,
My own experience is that the HP49G is a fine machine IF YOU KNOW HOW TO DRIVE IT! Comming from a HP48 should help, however I came to the HP49G via a much loved HP67 and the HP32SII. I now realise is that I want an HP42SII (along with every other reader of these pages! HP take note.)
Phisically:
It's big and its heavy - pocket calculator it aint. It's too bright and garish (professionals don't like this) The slip on cover looks cheap (to me) You have to press quite hard on the rubbery keyboard The screen cover reduces the contrast
The above are only minor points and you do get used to them.
The manual that comes with the calculator is just a short introduction to the machine, no more. The on-line manuals are not much better only giving you a brief introduction on each subject, there seems to be no progression of ideas - ie you don't build a knowledge of the machine as you progress through the manual. Every part seems to have a moronic attitude of: 'you press these keys to get the following result' and this does not teach you much.
I have not found ANY (official) info on how to program the calculator in RPN mode.
I love the HP67 manual because it leads the reader through mastering basic topics and going on to more complex ones.
Sorry if this sounds like I have something against the HP49, I don't, it's just the manuals are soooooooooo bad for me.
I have written technical documents myself and I guess the people (or managers of those) who wrote the ones for the HP49G have lost the plot. Early HP manuals seem to be written by people who realy USED the calcs and were able to pass their knowledge on.