We'll all have different usecase so I'll only talk about my own. I'm not a "mechanical" keyboard enthusiast myself so I'd approach this slightly different to m

We'll all have different usecase so I'll only talk about my own. I'm not a "mechanical" keyboard enthusiast myself so I'd approach this slightly different to many others I think. I generally like a narrow, low-travel keyboard with a trackpad or trackpoint. i.e. a laptop sitting centrally below an external monitor. I value symmetry. So I try to get the same modifier keys for each hand to make touch typing easier. That's not always possible with a laptop which would be a good reason to make something custom. I dislike number pads and mice as I think they pull right hand off centre, which leads to discomfort long term. I guess the perfect design, from my personal perspective, would hinge on if you can get low travel keys for an external keyboard build or not. Myself, I can compromise with just sticking to a laptop and a non-qwerty layout all the time but it does mean that I have the same keyboard when I'm travelling away from my desk.