[Aardwolf]

The hp-50g is pretty nice (I know I know, unpopular enter key location), its USB power and SD card make it quite convenient. Of course the screen is the same as before, but the CPU is faster afaik

And then of course there are many HP calculator emulators and others for android

[jasomill]

The 50g screen has only slightly (131×80 vs 131×64) higher resolution than the 48G series, but it has vastly better contrast, and, thanks to improved fonts and other UI improvements, the built-in software on the 50g also makes significantly better use of the limited screen real estate.

N.B.: Meta Kernel[1] provides many of the 50g UI improvements on the 48GX — 49g/50g OS is based on Meta Kernel — but installing Meta Kernel in RAM requires a memory expansion card that, at current used prices, costs nearly as much as a used 50g (plus a steady [semi-yearly IIRC] supply of CR2016 coin cells to sustain the RAM card when the calculator is powered off).

While I also prefer the aesthetics and keyboard layout of the 48 series, the 50g with its bundled software suite stands as one of the most hacker-friendly handheld computing devices of all time: while documentation and development tools for the 48 series were widely available, it wasn't until the 49g that self-hosted versions of these tools (System RPL (de)?compiler, Saturn (dis)?assembler, library creation and extraction tools) were bundled with the base OS.

[1] https://www.hpcalc.org/details/213