When I bought my first HP calculator, an HP 32SII, it was the manual which impressed me more than the calculator.
The calculator was very nice, but I had had some other Casio and Sharp calculators that, while being in the algebraic style, were also well thought out and quite usable.
But the manual was on a planet of its own. It was written in an outstanding way. It was clear, from the manual, the enormous amount of thought and engineering that went into that calculator. Other calculators were composed of many functions, more or less put together on top of an algebraic setting. But it was clear from the 32SII manual that true engineers and mathematicians had worked at the calculator. It was not a toy, it was the outcome of very sophisticated thought. The impression of quality, attention to detail, was remarkable.
The 33s, which I just bought, had a similar manual.
The manual is part of the reason I never liked the 48, 49, 50g series. The manuals were hastily put together, poorly organized, too large -- a sloppy job. And worse, those calculators were never really useful to me if I did not have the manuals nearby; never being able to use the calculators alone, I never grew fond of them.
The 35s has also a decent manual, but not in hard copy. To me, that is just a statement of cheapness, and lack of attention to quality. I find it strange that the cheaper 33s has a printed manual, whereas the 35s does not. It is as if the 35s wants to be a status symbol, rather than an actually useful calculator.
This, to me, is also apparent in other choices of the 35s. The ALL-digits mode is broken, the comma does not appear while typing a large number... yes I heard explanations for the latter, but when I got my first HP calculator, that incredibly useful shifting comma was one little detail that showed the attention to design that had gone into that calculator. Losing that in the 35s is just sad.
I don't buy the argument of going green. If you do care about being green, stop (as I have done) reading newspapers on paper, and read them on the web. I must have saved over ten pounds of paper a week doing that. I think all my HP manuals weigh about 5-6 pounds; my purchase of manuals is a tiny percentage of the books I buy. But for me, the presence of a manual is a sign that the calculator is created to be really used, as a professional, well thought-out instrument.
We will see if there will be models following the 33s, which I now consider to be the last of the classical calculators (the 35s does not qualify due to lack of manual). On some level, calculators will cease to make sense. Everybody will soon have a smartphone (an Android, or Pre, or iPhone, or...), and that will work as a calculator too. I am not sure of what the market will support; it will be interesting to see.
Luca