I'm not exaggerating at all - my NAT is open fine - tho it only takes very slightly longer with it closed.
It takes far longer than any server browser - I literally can spend upto 10 minutes at a time trying to get into a game, through the frequent host disconnects, lobby closed, migration failed, etc. and then half the time when I get in a game its really laggy, right near the end of the game or I get in and 1-2 maps later host disconnects/migration failed and I'm back at it looking for another game.
Some game modes are worse for it than otheres - I play a lot of groundwar which makes it worse - but other modes aren't that much better.
I'm not sure how I can exaggerate much anyhow... those are the hard figures taken from steam community and barracks, 300 hours on one 156 on the other.