Yeah. I am firmly in the "Everyone post your actions, and I as the DM can sort it all out in a end of round post," camp.

And if anything happens, like a spell drastically altering the battlefield or the number or locations of valid targets, you can always let the players whose actions are affected know.

It makes it way easier than waiting for one player to post, and then waiting for another, etc.

You can also, if it gets to be a problem, especially with so many of us in one group, make a time limit for us to get our actions in before you default us for the round.