What exactly is wrong with the si-design.co.uk download method?
Because that relies on one person - simon - contributing to the codebase. No-one else can work (in a controlled manner) on the code.
Now, simon may well want to retain his own version independently that only contains his (or his approved) changes, which he is of course entitled to do, and I can fully understand him wanting to do so.
But assuming simon is happy for a public, modified version to exist under (say) the GPL, it can only be a good thing to develop that on a CVS or SVN system that many people can contribute to. Better that, and have a single version, than 5 different versions with different tweaks.
So, to reflect your question: What exactly is it that you have against open source projects skid?