I thought average WPM was only about 40 wpm, and isn't a 'word' 5 chars including space? That would make the average typist not particularly fast, which is probably what you'd expect.

I agree that the space-as-shift thing doesn't work well, I tried it at one point. Space is hit so frequently, and worse, often just before a capital letter, which causes space-as-shift to fail.

But we are talking about something different here, as normal usage of spacebar is unaffected.

Using AltGr for shift is nice, you can easily reach all the other keys to make capitals OK, and is better still with the Wide Mod.

The final piece of the jigsaw then, is the method to get the AltGr layers (3 and 4), which after all, are usually less often needed than shift or space. But even so, the way to invoke them is quite simple once you learn the technique:

Your right thumb is over AltGr, and your left thumb is over Space. You press and hold AltGr, then press the spacebar, then release AltGr. It's kind of like doing a drumbeat but with the second beat held down. With the left thumb still holding space, you can now type Layer 3 characters to your hearts content, without your hands leaving the home position.

Layer 4 is similarly achieved, except you don't let go of AltGr.

I have since found another nice option. By making AltGr a sticky shift key, you have the option to not even hold it down to generate Layer 3. You would simply tap AltGr, then hold down space. Layer 3 magically activated. For layer 4 you'd need to hold both keys down.

The description sounds complex but the action is in fact very easy and comfortable to do.

No, 480 BPM is not too fast for a note! A song of 120 BPM may easily have semiquavers, and one of 60 BPM may have demisemiquavers (etc), which both equate to 480 BPM. In fact, I think that piano notes may easily be faster than at least my 70 WPM typing.

Of course, most chords aren't played quite that fast, no. The typing chords I'm talking about don't have to go quite that fast I think. Shifted characters are twice as much work as unshifted, but that's the way it has to be. And AltGr characters are rare, usually well below 1% of typed keys. So you won't be speed-chording.

I agree with stevep that words are five characters including spaces/punctuation, and furthermore – so does Wikipedia!

Thanks for that infographic, Cevgar! It's really interesting. Yes, it seems strange that the average is only 41 WPM because it seems everyone I know are typing rather quickly. But I guess I just move in circles of fast typers (academics, for the most part). And among Colemak enthusiasts I'd guess the average is at least 55 WPM, since we're a keyboard-oriented bunch. But it's probably lower than what most of us feel it to be – my gut feeling is that everyone and his dog here type at 80+ WPM but I don't think that's right. I think the fastest typists are less afraid of stating their speeds, so there's a report bias.

So... when/if I reach my long-term goal of 80 WPM consistently (at 98+% accuracy), I'll be in the upper speed range of "professional typists". Interesting. :-)