Yes, I think you must.
The Infected aren't necessarily the most pleasant of fellows to meet, but the storyline is worth every one of them plus more.
Noo, I am starting to feel like I have less time for it. But then sometimes I'm really stubborn and say I WILL play games, and then stay up later than I should. xD I think when you have really little time for yourself, when you finally do have free time, you're so weary and tired you kind of end up trundling really slowly through the things you have to do. :/ Or sleeping... xD