It's pretty good, I tend to think it has the potential to be as good as SWAT3 but it needs some fixes and mod tools and for people who can make it work to get behind it. I don't happen to think the dev team are as stupid as the anti dev/VU propaganda claims (cue the silly fanboy remarks and abuse one sees whenever one refuses to totally rubbish a games company like the rest of the herd), but it was designed in my view to win in fans of RvS not necessarily fans of S3.
Agree with the furball - could really be something. Will it? Who knows. Much depends on what happens next in terms of support. As it stands it takes some work to get serious coop going (and I am only basing that on preview code games with journalists of dubious tactical persuasion) but it does have a decent feel (though I can list numerous things I'd like tweaked). When S3 was released it was not the game it ended up being..potentially this could be the same.