Just made the jump from Advanced to Expert and DAMN! Big changes!
 
      To put it into perspective, in expert mode, each slash from an infected takes away 20 of your 100 health. My years of studying basic math tell me that 5 hits from a common infected will incapacitate you. Yes, common infected. You know the hundreds of them running around? 5 hits and you're down! One hit from a witch and you die instantly. This sort of scared me at first. However, if you work as a team and use items when needed, then it becomes a very fun experience. Everyone has to stick together at all times or else it's over. Friendly fire is more dangerous than ever. One shotgun blast will usually incapacitate.
 
     Please no one take this to literally mean "You are not playing l4d2 if you're not on expert." That's not what I mean. What I am saying, however, is that expert is a completely different experience. I'm gonna be playing on this for a while. Then I'll make the jump to realism, hopefully.
 
My GT is Skillface if anybody wants to add me and play! Happy L4D2ing and Merry Christmas!

I always play on expert 

I like realism myself.  Makes it more tense when all your trying to do is keep on eye on where everyone is;)

Realism, Expert, Hard Rain, without using an external voice chat program,   is awesome.
 
When the rain picks up your mic volume goes way down to where you can barely hear your teammates shouting over the noise of the rain. People getting incapped in the sugar cane field is hilarious, because its so hard to find them. They have to keep firing their pistol into the air so you can see where they are.

Its so much harder than the first game, anything past normal seems extreme to me

Totally agree...It's a lot of fun playing expert with friends, and we all got the achievement for finishing all campaigns on expert as well. It did take us a few times getting the Parish finale, that was a bit hard (took us probably about 30 mins of retries).