In any case I'm more concerned about the number of bugs I've noticed in various missions while playing the game, especially towards the latter stages of the game. Most I've managed to work my way around eg. your companion Cass' quest versus Crimson Caravan -- the mission line got stuck for me, probably because I'd already taken out the Van whatever-they-were-called in Freeside for the Brotherhood of Steel. So when I discovered the second lot of evidence, Cass didnt respond and I got no link to the next part. Eventually stumbled upon the Ranger in the camp where you first meet Cass and gave it to him thereby finishing it, but it was a total fluke. Cass kept indicating the whole time that I should have let her be with me with I took down the Van whatevers.
However currently the mission that is causing me the most headaches is one involving the Omertas, in particular Cachino. Ever since I first talked to him, he's been standing at one of the elevator entrances on the suite floor and hasn't moved an inch since then. I'm pretty certain he isn't meant to be there. The problem is when I finally get to the mission where we are meant to meet the two bosses of the Omerta's gang for a showdown, Cachino does basically says 'Lets go' and then does nothing and the actual showdown doesn't trigger. From then on if you try to talk to him he just says he can't talk now, or something along those lines. I'm guessing anyone who hasn't had Cachino appear to get stuck somewhere hasn't had this problem. I'm currently working on getting Joanne the hoker out of the club to meet with her boyfriend, an ex-Omerta. Am wondering if that needs to be done before the final mission with Cachino, but would be surprised if that is the case.
One bug that I think has been mentioned that I'd like to doubly confirm is that with certain clubs on the strip when you enter/or exit them (not quite sure when exactly it happens as I can't find where they actually store your gear when inside the club), certain weapons have disappeared randomly. The one that seems to be most consistent is the experimental named plasma rifle that IIRC comes from Repconn Headquarters. I gave Boone that and every time I exit The Tops (I think it was), it wouldn't reappear in his inventory. In any case I highly recommend leaving your companions outside whenever you visit one of the casinos.
Speaking of which I've had various oddities happen with companions, not equipment, whenever visiting The Fort -- the place where the head of the Legion sits. I've had Rex disappear and not been able to find him after coming out of that tent.
Also in The Fort there is a little slave girl who has had her teddy bear stolen by a guy who trains the dogs. For some reason after I fought the guys dogs in the arena and he gave me the bear, she was nowhere to be found when I went back to her enclosure. She hasn't been there since. So that's another mission I can't complete.

While for me New Vegas is one of the best Fallout games ever made (I'm a big fan of the original 2 games and not such a big fan of Fallout 3 which was too easy and felt more like Left4Dead in too many places) I feel that they've somewhat rushed the release of the game and it's not all it could be as many of the later missions lack polish or don't work 100% properly. In any case I'm planning to play through again and this time take notes on where and what bugs I find with missions, just hope they already know all of them and will fix them in an upcoming patch before I get too far.
