First the show is neither great nor bad, it's just another inspired by from a book story with some really good actors and some good new faces. The story though should scare everyone because it is when not if we will see Ebola outside of Africa again. The dramatization to push that point home is where the show differs from the book, facts, and the actual true story based on several articles I have read.
I've not read the book, but I have read articles checking on the story accuracy and it probably deserves a C at best for how faithful it is and an A for making sure to repeat the words that it is inspired by a true story. Some of the errors are general that things are/were simply not the way it is told, and some of the errors challenge the words inspired by because the story is changed from the actual events in fairly dramatic ways.
Having said all that, it's better than many other stories (like the Spanish Princess for example), and the acting is considerably better. Take the review with a grain of salt as 5 people rated this at 4.3 before it even aired, and as you can see for another review someone watched 5 minutes and made a decision.
If nothing else, it should scare the absolute socks off everyone because where the story deviates from fact, it shows us what it could be like old Europe with the number of dead we could have had.