I will admit that there was some dull levels of Spec Ops. Gladly though, I found the wave survival missions the most interesting and challenging (yet not camp on the catwalk challenging like zombies).
I have high hopes from what I have seen for it so far.
From what 402 said it will be challenging. At least there will be a real threat other than lag and Zombies with arms that stretch.
Yeah I played BO zombies and I got to like round ten the first time I played with my two friends and it was just so boring, but MW2 spec Ops was so great from the get go and every one was different and took a different set of skills to complete which made it interesting. I believe that survival mode will be intense enough to keep me interested and the avialable upgrades of perks and streaks and all the different little things to customize will be amazing.
Well survival mdoe has 4 people too. But IMO suruvial mode looks more epic and they also use multiplayer maps. So when the next DlC comes out, they have one just for survival too and multiplayer