The problem? Since the mid 1970s (when I stopped using books of log and trig tables) I have been accustomed to typing the number followed by the function, i.e. 32 sin. This new calculator (£6.50's worth of W.H. Smith's finest scientific calculator) throws all that out of the window. You have to enter the number, press the, say, sin key and then press the = key. What a sodding palaver.
I think that was something Casio came up with in the mid 1990s
[1], as I remember seeking out the most functional exam-legal calculator, and it was equipped with this Shiny! New! VPAM technology.
It didn't bother me especially, as by that point I was used to a non-exam-legal programmable graphing model, where entering compound operations in a computery style followed by the enter key seemed entirely reasonable.
TI purists will be along in a minute to explain why reverse-polish notation is the One True Way...
I've barely touched any of my calculators since my PSO days, as the correlation between needing to perform some arithmetic and having a Turing-complete computing device in front of me, or at least in my pocket
[2] has been approximately 100%.
[1] The development of calculator technology ground to a halt at around the same time that the development of printers did.
[2] Very occasionally I fire up the excellent TechCalc on my phone. It's the sort of thing my teenage self would have loved, but the reality is that entering more than a handful of numbers on a touchscreen is nasty.