Now that it's 20 bones and it as The Passing...

Due to achievements, I got back into the original L4D recently and then I realized how more awesome L4D2 is so I finally said I should actually buy that game.  Now that Steam throws a 33% off sale on it making it 20 bones, it looks really enticing.  Besides the game now has The Passing which should be fun for the whole family.  Since it will be included into the cost (hey it's free after all!) should I get it?
 
I just want to make sure because I'm a frugal bastard.
 
EDIT:  The search feature to attach to a page didn't work so there.

It's more of the same, for better or worse.

Imo it got boring fairly quick.