I think its better than the original because there are more zombies, more weapons, and more special infected. It actually is quite a bit longer than the first
especially with THE CENTER served on HARD.
the number of run around, getting tanked, charged, constricted is so high as you run up the stairs with zombies constantly behind you to get fuel is TRUE SUSPENSE.
something l4D itself will never have.
L4D is easy, formulative, while where crawling is concerned, L4D2 significantly places you very far away from your target and these missions are hard core hard if it is meant to be. The number of extra special infected means age old theories of hide in a narrow corridor doesn't work (Spitter) and if you plan to solo you have Jockeys, Chargers are like small Tanks, and easily much worse because of their single hand damage.
It is a new playing field, and if you are not impressed with the first one you are unlikely to enjoy the second one.
I am just waiting for the Miku Hatsune mod for now.
(the one for the Witch, the Taiwanese version makes her growl, and then yell Onii-channnnn when she is chasing you (even if you play Rochelle))