As a slightly better than novice website coder/designer/builder (whatever you want to call it) my current sites are all built using HTML. As with most things, the more you do it , the better you get / the more you learn yada yada yada. Well, I have learned that HTML can be a pain in the backside when you have multiple pages and want to make a sitewide change.
Granted there are tools to do a find and replace such as in Dreamweaver but as you may know, unless the what to find portion is exactly the same on every page, the replace function will not be complete - it could even cause some pages to fail.
So, having an html template comes to mind - that's nice and all but, I don't see it being the solution to sitewide modifications.

I have begun to learn about CSS and used it for as a basic style sheet ( mostly just for setting text / headers and such).

My question then is "Who out there is using Joomla (joomla.org)?"
Do you like it, is better or worse than pure CSS / HTML?
Granted, joomla runs under Unix but that opens up a completely open source website. This means getting some knowledge on the best choice for the OS - Knoppix, etc.