Hello everyone!
As promised in the General section, I'd like to make a quick post about my experience with Colemak. Let me first give a very short introduction: I started touch typing on QWERTZ, this is the German QWERTY layout (Z and Y are swapped on the German keyboard) and I was pretty good at it. However, as the German layout needs Umlauts (ä, ö, ü), a lot of less common keys (e.g. square/curly brackets) are in very awkward positions or can only be typed using an "ALT GR" key combination. This is fine if you type text most of the time, but I have always been a hobby programmer and now do programming for a living. As a programmer, you need those less common keys pretty often and thus I switched to the US QWERTY layout, just because of those keys. This made Umlauts impossible to type, so I stopped using them in German texts. You can replace them by ae, oe, ue if you have to. Hardly anyone does that nowadays, but most Germans won't have a problem reading that, especially since the pronunciation of ae, oe, ue pretty much equals ä, ö, ü. The two dots were originally two strokes and two strokes evolved out of a the letter "e", see here for details. I even did so in official documents and nobody ever complained about it. I know some other programmers that do that as well, and for all people that learned German as a 2nd or 3rd language it may also be more comfortable to use their "native" keyboard layout, which often features no Umlauts.
About 6 years ago I discovered Dvorak on the Internet and it sounded like a great idea to me. I always knew there must be something wrong with QUERTY, as the layout doesn't make a lot of a sense from a logical perspective. Being a programmer, I like things that are logical and I couldn't find out what logical pattern QWERTY should be following (common keys are not in easy to reach positions, frequency of keys is totally unbalanced between hands, and so on), thus it was illogical to me. Switching to Dvorak was really hard and it took me about a full year to get close to old speed again; however, I didn't switch to type faster, I was fast enough before. I switched to type more comfortable, it's all about ergonomics to me. I would always accept a slower typing speed if that means a less strain to fingers and hands. About the same time I also switched to a Mac computer and that had a huge advantage: Even though Dvorak has no Umlauts either, I was finally able to type them again. On a Mac you type ALT+U to just get the "two dots" as a dead-key, then you type a, u, o and you get the appropriate Umlaut. Not that this is very comfortable or fast, but good enough for the few German texts I had to type.
Am I unhappy with Dvorak? Not really. Using a different keyboard layout than pretty much the rest of the world surrounding can be annoying, especially if you have to use a computer that doesn't has the layout available and you have no way to get it there, but nowadays almost every OS has Dvorak as option available (I guess many people here wish that would be true for Colemak, too). Dvorak might have some downsides as pointed out in the FAQ of this page, but maybe except for the L position, I never felt like any of these are a real problem (e.g. neither typing ls (LS), nor having Cut/Copy/Paste in a different potion ever was a problem for me). Dvorak is definitive good layout, no question, but that doesn't mean Colemak cannot be better :-) Programmers also tend to head for perfection, so if Colemak is maybe better than Dvorak, why not using Colemak? At least I should give it a fair chance, so here I am.
The main difference I have noticed so far between Dvorak and Colemak is that Dvorak focuses more on hand alternation, while Colemak focuses more on combos (e.g. a rolling motion). There are many arguments what is better and so far I'm not convinced that combos are so much better. E.g. the following post came to the result, that neither full alternation nor full combos are very fast. If some key combination is very fast, it is usually a combination of both. However when something is slowing typing down, it is rather a combo than an alternation. Actually alternations have the lowest "worst case" potential and the worst cases are what slows us down the most.
The following words (words that I type more frequently) are very hard for me to type in Colemak, as they are either typed (almost) by one hand only (I'm not used to typing that much with one hand only, remember, I'm a Dvorak user), may use the same finger twice in a row or are otherwise somehow unpleasant or awkward to type:
online, data, cd, cat, atx, http, anime, gcc, xargs, status, kill, password, sparse, text, mpg, file, again, xargs, you/your, as ... as, void
And I just found out that the following phrase is entirely right handed: "join me in"
We will see, if that is just, because I'm currently still an extreme Colemak beginner (doing Colemak by night and Dvorak by day, since the layouts are so different that I need a hard cut between them!) or if they will stay hard to type.
Dvorak is not that alternating BTW. I wrote a little HTML page with some JavaScript code to better visualize hand alternation. You can feed some text to the JS code via a text field and when you hit the button, it will print out the text three times, once for QWERTY, once for Dvorak and once for Colemak, coloring all letters written by the left hand in blue and all written by the right one in red. For most texts QWERTY and Colemak are pretty similar, QWERTY favors the left hand, while Colemak the right one. Dvorak looks more balanced IMHO and while some words are highly alternating (e.g. "sometimes"), most words consist of two or three consecutive right hand keys, interrupted by one or two consecutive left hand keys (this is probably because all vowels are on the left).
Two final closing comments: German and English have a very similar letter frequency (except Y, which is almost unused in German, that's why Y and Z are switched on German keyboards) and also many similar two letter combination (with the exception of "th" which does hardly exist in German at all), so I don't think Colemak will be a problem for German texts. You can see this pretty nice looking at that this picture.
And last but not least: This post was made during the day, thus it was made with Dvorak. If I make a post during the night, don't expect it to be that long ;-)