I love this game, but as it stands right now, while there are multiple paths to take, on a whole lot of levels, all one team needs to do (generally the resistance) is sit on top of a door while the security guys get torn apart trying to plant a bomb or repair a crane or escort a bot or whatever. This wouldn't be too much of a problem if the teams were actually organized, but I think its a bit unfair to ask public servers to have huge amounts of coordinated cooperation for a mission to be remotely possible (maybe i'm wrong in saying this).
Personally, I think that an easy fix for this would be just make the amount of time it takes to do an objective (hack something, repair a crane etc) shorter - for example, after having played shipyard plenty of times, as Security only once have I had the crane repaired - and that's not even the end of the mission! Then you have to try and hack the missile which is equally hard when all the resistance needs to do is sit on the box and undo any little your team might have hacked. There is a lot of talk about the spawn points being unfair, and I agree somewhat, but I think decreasing the amount of time it takes to do objectives considerably would allow a lot of maps to at least advance beyond the first instance without having to change map design. Further, it would decrease xp farming by resistance members who just keep voting for shipyard/container city (both very fun maps if you can get somewhat further along in them) and then destroying security teams who don't work together like they've been playing together forever.
Anyways, cheers, and sorry again if this is redundant.