My concern with a device of this size is typing. How do you use a keyboard barely larger than a credit card? Do you thumb-type, touch type, hunt-and-peck with just your index fingers?
You'd be surprised. On the GPD I had, I managed full 10 finger typing (albeit one finger at a time). It worked surprisingly well and I managed to code at a good enough speed that I could be fairly productive on it.
Somewhat similar, but I owned a Toshiba Libretto back in the late 90s and the keyboard was quite compact. I could still touch type even though my fingers were all right next to each other, so it's not a deal-breaker.
> How do you use a keyboard barely larger than a credit card?
If you can use a phone's virtual keyboard, which is even smaller and has no physical separation between the keys, you should be able to use a keyboard like that one. It feels strange at first, but you adjust quickly. (I don't have any experience with that GPD, but I have experience with an old EeePC, which is similar-sized but probably has smaller keys because it doesn't have any keys to the left and right of its trackpad.)
A phone keyboard supports swiping for words and never requires multiple buttons to be pressed. Tapping on a small target is one thing; trying to hold down a modifier without pressing adjacent keys is something very different.
I am proficient with phone keyboards, but part of that proficiency is almost never using any punctuation, numbers, or symbols that aren't on the primary screen. Once I need anything more specialized (say if I wanted to do any coding) my speed drops by a huge factor.
I can hold my phone in one hand, and type with just my thumb, and my thumb covers the full spread of the keyboard. Or I can type with two thumbs for things that are longer than a few words, and again reach the entire keyboard without shifting grip.
But also I don't type much - in fact as little as possible - on my phone, and certainly not code. I will switch to my laptop for anything more than a few words if it's possible.
It is one of those devices I could see always carrying with me but only using in emergencies. It has HDMI, Ethernet and serial ports. What more could you ask for?
