Using the keyboard has always been my main interface to computers. When I first started using our 286 back in the early 1990s, which I shared with my older brother, the computer booted into a command prompt and that was it. We had a fairly solid German style keyboard with clearly audible click sounds. So naturally my first attempts at typing were based on a QWERTZ keyboard layout, which was perfectly suitable for me, until I dove into programming a few years later.
The thing with programming languages is that most of them require special characters to be used fairly often, e.g. curly braces {} and brackets [] in C, backslash \, at-sign @, pipe | and others. These characters are accessible via the Alt-Gr or Right-Alt key on German keyboards in combination with the upper right digit row - 7, 8, 9, 0 - which in my opinion is not the most comfortable finger position for the right hand. The programming languages I chose at the time were based on the English language anyway - e.g. Pascal with 'begin', 'end', 'procedure' etc. - so I switched to US keyboard layout, at least for programming tasks. Most special characters are easily accessible using either one of the Shift keys plus a number key or one of the non-alphanumeric keys. I remember that by switching the layout alone, programming instantly became more fun due to less strain on the right hand.
After years of using both German and US layouts I was quite comfortable typing without looking at the keys and at least for command line input and programming tasks my typing speed slightly exceeded the average. But since I never formally learned ten finger touch typing it was more of a 7 to 8 finger usage. There was definitely room for improvement.
In April 2004 mostly out of curiosity and to refresh my mind I decided to try the US Dvorak keyboard layout as seen above. There are numerous alternative layouts like the rather popular Neo2, but the Dvorak layout dates back to 1936 and has since been implemented in a vast number of old and new computer systems. That means even when I encounter some strange old Spark station clone or whatever ancient computer system is still functional, there is likely a Dvorak layout option available. The Dvorak layout was invented to be more ergonomic than QWERTY when entering English words and therefore decrease stress on fingers and increase typing speed. These claims are somewhat controversial and were never scientifically proven. But personally I found it tremendously easier to relearn an entire keyboard layout rather than trying to fix my QWERTY habits. This argument is not for everyone, but since I am mostly using my own computer and I do not have to share my keyboard with anyone, the step to change the layout entirely fit perfectly to my needs. Also, the fact that I was already familiar with the US layout helped a lot, because all keys on US Dvorak layout are just rearranged from US layout. That means all the special characters behind the number keys remain exactly the same and all special character keys still have the same Shift/non-Shift assignment despite being located somewhere else on the keyboard.
The other thing that is generally somewhere else on Mac keyboards vs PC keyboards is the entry of German umlauts and French accents unless you are using the respective local keyboard layout. Mac has the umlaut character - Alt-u - followed by the vowel and accents are entered in a similar fashion. On PCs there are numerous methods to access language specific characters, but let's just say, it's complicated. I usually stick to using the Mac for writing non-English texts. If I have to enter German text on rare occasions on Windows, I tend to switch the layout using Alt-Shift for umlauts and then switch back to Dvorak. Eventually I would probably use US Dvorak International layout, which gives access to umlauts via Alt-Gr.
In order to initially learn finger placement and start typing at reasonable speeds, I used a tool called DvorakNG. I suppose there are equivalent online tools nowadays. While learning, some keys turned out to be too far away for my hands while resting and I would rather have my hands rest comfortably than constantly move up and down the rows. So my ten finger system is slightly more personalised when it comes to upper left and upper right keys, that are ordinarily entered using the little finger, but I am using the ring finger instead. As far as I can tell, this slight change has had no impact on my typing speed.
The change from QWERTY to Dvorak took me about two or three weeks in order to regain my former typing speed back in 2004. But was it worth it? Definitely. Apart from typing a lot more accurately, typing Dvorak helped me a lot to not think about typing itself but rather thinking about the content, the problem at hand or entire sentences that magically flow into the keyboard. Would I recommend that journey to anyone? Probably not. The switch helped me personally to be more efficient. But you can be equally efficient without switching. My original reason for switching was that I am generally curious about many things and by learning a new skill I can refresh my brain in a potentially very useful and practical way, which turned out to be correct even now, 18 years later.