For what it's worth, I also think the HP-34C is a great machine, and I'm not the only one to think so, several of my HP-fan friends do agree as well.
I was delighted to get one when it was released, and I liked very much its advanced features, Solve and Integrate, which were so incredibly well described in that legendary HP Journal issue from 1980 (IIRC) by their "father", Mr. Kahan.
The fact that Solve could use Integrate and vice versa seemed to me incredibly powerful as well.
It also had a lot of good 'physical' points. For once, it seemed solid, the keys had a very nice, positive action, and the LED display was marveously clear, and of course, you could do what you couldn't with any of the later models: to use it in complete darkness !! I was very young at the time of its release, and I was enthralled to use it at night, while in bed, without turning the lights on and without disturbing anyone. The LEDs were bright enough to easily
see the keyboard legends in full darkness. Try that with a 32S, 41C, 71B, ... !
Another good point is that it had a lot of memory for the time, and combined with the advanced programming capabilities, you could write quite complex programs, which wouldn't fit in a basic 41C, specially if they also made use of Solve/Integrate. Matter of fact, many of those programs wouldn't fit in a 32S/SII as well, because the Solve/Integrate functions in these models take a lot of the already small memory, leaving very, very little for your program/variables, also using more RAM per step (from 1.5 bytes upwards).
So the HP-34C was much admired, and sold very well. I still have a large number of advanced mathematical programs for it, and still remember how much I enjoyed writing them and seeing how easy it was and how well they fit in such a tiny but powerful calculator.
Finally, the HP-34C had its synthetics too !! There were a number of very interesting articles published in the state-of-the-art Australian PPC Technical Notes, dealing with ways to access different parts of the RAM, the Solve/Integrate registers, the decoding of the full hex table, etc, etc. It was awesome what people could do with
this small marvel.
Definitely, you're not alone in your praise of it.
Long live the HP-34C !