Joomla

Open Source System
Good for blog entries
Easy to install

There are not many third party integrations
The community of users isn't big.
Customizing any website requires a lot of work and there is few an little quality premade layouts available.

It has to be that it works logically and makes sense, if there is a problem you can usually work out what has caused it and fixed it without much of a problem. If you do get stuck then there are usually places where you can find answers to your problems online

When coming to technical SEO issues for things like increasing page speed, removing unused Java script & CSS etc most of the tutorials online seem to be focused more on different CMS users like WP etc, it would be great if Joomla did actually have some paid employees who could create useful guides for non coders who aren't experts that could make some walk through guides so the average user could make their own websites run like experts sites. I know Joomla is an open source software, but I wouldn't mind paying a small fee when I set up a new website to contribute to having some full time paid staff who could provide more documentation and training for Joomla, as opposed to having to paid large fees to experts as that's not really in my budget.

The best about joomla is that it is very powerful and adaptable. I has a big community, thousands of sites made with it have created an enourmous community of developers and designers who have experience with it. That also means that is has a huge assortment of plugins, extensions, themes and whatnot.
Its very likely that whatever problem you have someone had the same problem before, so solutions will be available in the form of plugins (sometimes paid ones), or forum posts. If you need to do something very specific that requires coding, well then joomla is simple php and js, meaning any developer can quickly fins his way around joomla.

The main con about joomla is that it is a bit old and unintiutive. If you have never dealt with a CMS then you might need to read some documentation to find your way around a joomla site. Even if you have used other CMSs, joomla has it's very own way of doing things, meaning that tutorials and getting started guides are a must. Plugins rarely work straight of of the box (or zip), they usually requiere a bit of coding to get them exactly like you want them, but that can be said about pretty much any CMS.