Which scanner did you hit it with? I've used 4 and they all hit within a couple of seconds. Print versions almost immediately. That said, the couple second scan times I was maxing at are not something I would ever release into the wild, but wanted to demonstrate something different to get people thinking about what they could do that's visually more interesting.
Anyhoo... I couldn't get to the page last night to continue my thought. If you do some searching, via "QR Code gallery" or some such phrase, you can find some interesting visual presentations of what you can do, beyond the standard black and white.
When it comes to customizing them, there's definitely some time and refinement involved as you try to achieve the balance of design vs. the issues Greg encountered. It comes down to working with the image, scanning with your code app, adding outside graphical elements, re-scanning, and arranging/resizing them until you get good response times. In the example I put up, the word "forum" caused the biggest problems, with fractional moves having a huge impact on scanner response.
So then what? Attach it to a useful landing page on your site, and Google Analytics, and you can capture some great customer info and data as to what may or may not work for your LCO's marketing efforts.
a guy who knows the lawn industry, branding, and web strategy