I think its a love/hate thing with my site theme. I've had a lot of comments that it looks fantastic. I think I'll have to increase the font size at least.
Don't increase the font size (it doesn't help). Even when they're larger, certain characters (ie - SQL) are completely unreadable. Script is always a bad idea on the front-end.
I also recommend choosing a more standard font. Personally, I left the site after trying to read the article and finding it a quite unpleasant experience to try to read.
There was a time when the web was content (or data) and it would look how the user wanted it to look, configurable via the user agent's preferences. In fact Firefox still lets me choose fonts (and tell websites that they cannot override the fonts). I use the feature for security as well as readability. I wonder how long it is until they decide to remove the feature because it breaks the web...
I am thankful you still had a choice to continue reading or not. I am thankful you had the choice to use a user-stylesheet to override both the font-family and the text colour into something more readable for you.
I am thankful that the ability to work around these shortcomings was in your control. (Chuck it through a readability bookmarklet, as an alternative to overriding CSS)
Spare a thought for people where the choice of whether or not to consume a piece of content is taken away from them because they are disabled, and they have no straightforward way of working around the barriers the website has placed before them.
These people don't have the choice you have, unfortunately. I wish they did.