Another +1 for the DM42 here. It's a great calculator and very nicely built.

It uses a transflexive memory LCD display, kind of similar to eink, which is a pretty good match to the application, batteries last forever, and the software is very good.

It compares very favorably to the HP-35s (and the WP34s) I was using prior to it.

It’s a beautiful machine, superb build quality, as good as genuine HP pre-Fiorina. If anyone is considering one, you will not be disappointed.

I bought the DM15L only a couple of months before the 42 was released and it's built really well.

I don't have the HP to compare the button feel to so it may not be exact (and there are differences in looks) but it's nicer than any other calculator I've seen available to buy today.

There’s less travel in the Swissmicros keyswitches, that’s the main difference. But it’s still massively more tactile than a touchscreen.

EEVBlog review:

https://youtu.be/Ong91Ji3iDk

And they use free42 under the hood :).