I've liked what I see on Umbraco so far as a CMS but I'd like to know if it is capable of scaling well and support high traffic if I have the right hardware (servers, etc...) and good load balancing ?  Is it a heavy CMS like Joomla ? I'm starting to think about my options but I want to make sure that I can avoid any future set back to my next project. Just to have an idea of what I'm looking for, I'd like to use Umbraco to build a website similar to this classified ads website or even something like Craigslist but whether this is the right framework to use is my question. I'd really appreciate any great feedback.  Thanks a bunch.