It's a very good show and pretty accessible as far as "quality" TV goes. I've used it as an entry point to so-called prestige dramas for a lot of people with plenty of success. Go for it.
I don't think it's the greatest show ever like some people do, but I find it hard to imagine someone actively not liking it. It's comfortably in my top 10 dramas, dunno exactly where it would land.