They are great for many reasons. Easy to care for, easy to clean, inexpensive and really good looking.
There are not so great things about them.
Anything you drop on them will break, crack or chip.. Consider area rugs.
When you stand on them for long lengths of time, your back will be killing you. Kneeling on them for any length of time is almost impossible. and sitting directly on them is very cold. Purchase standing pads for areas where you will need to stand for long periods.. In front of work counters or craft counters, sinks... (I worked retail on one for 5 years)..
And they are not acoustical, so you will need to figure out how to buffer sounds. If you whisper on one side of the room, you can hear it on the other.. If you have the TV or music playing, unless it is really turned down, it the sound bounces off of every wall as well as the floor.
When they get wet, they are very slippery.
The store that I managed with the stained and sealed concrete also had so much traffic on them, the stain did wear out on the main traffic areas. I am sure you will not have thousands of people walking the same path through your room, but it can happen over time.
As you can see, as long as you are aware of the downsides and deal with them they can be great!