I would also like to highlight 3 issues that you would like to know when you manage Joomla:
Joomla is free which means anyone can download it and look at the code. When hackers find a vulnerable Joomla site, the hack is able to break the password protected CMS portion of the site and upload ads for pharmaceuticals or pornography.
On the other hand, good guys from all over the world also look through the code to find security holes to report them or to provide fixes to the community. Joomla team periodically issues security fixes indeed. Please subscribe to their mailing list to be aware and to make ontime installations.
When you are editing content and try to bold a few words or highlight certain words using a different color of text or something, Joomla may add styling code to the backend that has to be cleaned out the next time you want to edit. If it isn’t, over time your font color, style, or placement may become broken.
The issue is that Joomla provides WYSIWYG editor for content submitting. It is intended for users not familiar with programming or HTML but who know user interfaces like MS Word. It is a very hard task to convert visually formatted content into HTML automatically. Therefore it is better to paste the written text to notepad, then to the editor, and then to edit it.
Customizations and upgrades
When performing customizations or upgrades do not touch Joomla core files, otherwise there may be damage to the system.
Joomla provides several ways for customizations: components, modules and plug-ins. Customizing Joomla with these methods doesn’t require core files modification. Thus, there are no problems with updates and no PHP knowledge is required in this case.
We choose Joomla CMS for projects because it provides good base platform to build on. Sure thing, any CMS applies some restrictions but Joomla provides a lot of basic functionality that you have to have developed from scratch otherwise. In most cases, Joomla is more convenient for our customers.