IP is really no different than GameSpy. GameSpy just hooks up the players - after the game starts its all direct IP anyway. IP connect just allows people to connect to a server without using the standard GS interface.
It takes me on average 1/2 hour to connect - several attempts. I wish it were possible to know if everyone had the right patch and had a non-corrupted environment prior to start, but doesn't seem that Firaxis has that capacity in this game as of the current rev.
Here's a suggestion. I've just started playing ladder games - cool thing about ladder is that if you quit, then you get a lower rank - so people are more willing to stick it out. Also, ladder players vouce for other ladder players so you know right away if someone has the right patch. Lastly, most ladder players are experienced enough to know when their environment has become corrupt and they need to reload the app or reboot (by the way folks, if you are unsure if you have a corrupt environment or not, just reboot and save us all the trouble : ).
One very active ladder is at:
www.myleague.com/civ3ptw but there are others as well.
BTW, GS is a great chatroom to find games in even if they end up being Direct IP games. I know many folks have the GameSpy chat open via the browser java applet and while they're pulling together a game.