Call me cynical, but I think a lot of the small style keyboards I see around the office are more of a fashion trend than anything. I remember when the insistence was on number pads, and how dare they be removed from our laptops and desktop keyboards. Fast forward a few years and I was made fun of at a programming job for preferring a full keyboard with a number pads. I guess programmers are too cool to enter in dolla…
The benefits are twofold, in my experience:
1. On the subject of a reduced number of keys
Every key is within 1 unit distance (ok, root(2) units for diagonals) of the home row. I no longer have any cause to remove my fingers from the homed position while I type. Ever.
Using (the usually criminally underused) thumbs to switch layers is great. Depress one thumb, and the numbers are now on the home row - no stretching or moving. The symbols which are usually shifted numbers are now on the top row with no need for shift. Depress the other thumb, and the cursors appear in the usual vim locations, with PgUp/Down and Home/End on the row above and special single-key Ctrl-Left/Right on the row below for by-word movement.
2. On the subject of grid layouts
I personally find the grid layout to be extremely ergonomic. There is no ergonomic intent in the staggered layout, and standard touch typing form requires a lot of bending fingers underneath or around each other.
Using a grid layout matches the mechanics of my fingers much more closely.
There are also a few keys near the middle of the board (B, Y) where it's not even clear in a staggered layout which finger is the natural one to use.
I started typing at the age of 6, hunting and pecking. That was 30 years ago.
Over the years I developed a relatively quick form of 4 finger per-hand typing, but with no proper homing - I could perform fairly long runs of typing uninterrupted based on knowing the keyboard inside out, but my hands would move all over, and I would have to look down frequently, especially after any pause, to find the first key I was going to use next (I could then proceed for a few words working entirely relatively from there).
I made several attempts to learn proper touch typing over the years, but it never went anywhere.
About 2 years ago, I got a Planck clone because it seemed like a fun idea. Within two weeks, and without any drills of training, I was typing entirely without looking at the keyboard.
It's obvious and natural which key maps to which finger.
In summary, the combination of no movement of the hands, and the grid layout (which actually is more ergonomic than staggered - no finger curling!) made typing significantly more intuitive. Especially as a programmer, for whom the symbols scattered around the right hand side, all intended to be operated with my weakest finger (I'm left handed) as an essential part of text input.
I'm still not a particularly fast typist, I never have been. But I find my built in laptop keyboards frustrating now and have no intention of going back. Small and stationary is beautiful, for me!
Just my 2c, as someone who actually uses one.