Hi jammycakes. I made the switch about six weeks ago and up until a few days ago, I too was obsessed with speed. I had been touch typing in QWERTY for about eighteen years and my speed was pretty poor, probably about 50-60wpm with fairly low accuracy. If I had made a conscious effort to be as accurate as possible, it'd probably have been closer to 40wpm. Part of what made learn Colemak, and Dvorak before that, was a desire to type faster with better accuracy. So far Colemak is doing a very good job.

The last few days I have been slowing down, typing in a bit of a jerky fashion, making a deliberate effort to make no mistakes. I think it is now paying off. I did a couple of typing tests at typeracer.com and my speed is about 50-55wpm, with only a couple of errors (up from mid to high 40's).

In short, I think worrying about speed is not going to help you type faster. Being accurate and relaxed seems more important to me. This from Ryan Heise's site may be of help:

Tips for learning

    * After the plateau at 50 WPM, I decided to pay attention to my weaknesses, and I noticed that my most commonly mistyped character was "G". After simply focusing on "G" as I typed, my speed instantly jumped up into the 60s.
    * When I got into the 90s, progress was quite slow getting up above 100 WPM. What helped was to practice by typing with a steady rhythm, using the same amount of time to think about each character. This forced me to take the time I needed to catch common mis-presses before they happened, something that I think would have taken much longer to correct otherwise.
    * Now that my speed is above 100 WPM, my typing technique works something like this: by default, force myself to type at a steady pace -- but, when I see words or strings of words that I know I can type very quickly (e.g. using known finger rolls) then I remember to speed up on those, -- and, when I see words that I know I have problems with, I remember to slow down and type carefully. This, I have found, is the fastest way for me to type, as it tends to eliminate a lot of wasted time introducing and correcting mistakes. However, it requires being aware of your strong and weak words.

How long were you typing in QWERTY  by the way?

Edit: One of the most compelling reasons for me to stick with Colemak is just how comfortable it is to type on laptops. I always hated using laptops with QWERTY, fingers dancing around like mad, failing to hit the right key. And that uncomfortably long stretch to the backspace key.

If you hit some problems, I'm wondering why didn't you just ask for ideas to overcome the problems instead of letting the frustration build up until you finally quit.

I'm a big fan of pair programming myself, and I didn't find using Colemak a big hindrance; a minor annoyance at worst. In the first case, the issue completely resolved itself when against all odds the other programmer converted to Colemak as well!

In the other case, I never found it to be a big deal anyway, as we generally just communicate to each other what to type, instead of butting in each others' keyboard. The other programmer knows that they have to hit a certain hotkey before they type (which is the same hotkey regardless of what keyboard layout active), and it's not that of a big deal. Specifically, the AutoHotKey solution solves most of the issues you're mentioning, because with AutoHotKey's the keyboard layout is global (not per window), and it can be configured to automatically switch to QWERTY whenever someone hits the Backspace key (so after a typing a letter wrong, and correcting it, it will automatically switch layouts). I'm sure that there are other possible workarounds as well.

As said beforehand, the key for faster speed is accuracy and rhythm, the tip by Ryan Heise mentioned above are very good. When you say that after a few months you're still making "just as many typos and mistakes", then perhaps not enough emphasis has been put in regard to accuracy. 

Sorry it didn't work out for you. On the bright side, now the "live webcam" on your blog will now match your actual keyboard layout.

I decided to watch the replay of Jammycakes's top Colemak score of 71wpm. I counted that twenty two mistakes were made, resulting in about forty characters that needed to be corrected. Had these not been made, his score would have obviously been higher. I'll bet that if he had slowed down a little and attempted one hundred percent accuracy, his score would have been at least 80-85 wpm. Maybe even the 90 he was hoping for...?

Jammycakes: I'm from England too. I use 'portable colemak' which as you may or may not know is based on the US layout. Double quote is swapped with the '@' symbol (Shift + ') position on UK boards. To me this makes much more sense. Also, CapsLock is available with Shift + CapsLock, which to me is perfect. Fingers remain on home row (as I mentioned in the technical forum). Would love to see this in a future version of Colemak.

I find it interesting that some people find that Qwerty is a better fit for them after trying alternatives. I'm in no position to challenge your experiences or conclusion, but I never liked Qwerty. It all seemed too much work for me. I am finding Colemak to be brisk walking compared with Qwerty's all out running. Each to their own as they say. All the best.