Why Grey Knight players love IG players (or should).

I wonder if other players out there agree with me on this thought:  I love Imperial Guard players.  As a current Grey Knight player I love playing against well played imperial guard armies.  Many of the games I have played against such players have been my most enjoyable games since the new GK book came out, and win or loss(most have been losses) all of them have been great close games.  The biggest issue I have being a Grey Knight player in the current 40k tournament scene is the amount of whining you have to deal with.  "Grey Knights are so Cheesey/over powered/broken."  "Your army is point and click."  "X unit is so broken, GK players should be penalized for taking it."  I'll be the first to admit that Grey Knights are powerful (even over powered compared to many books), I'm just sick of hearing about it.  Which is why I love IG players.  I never hear these guys complain about how broken GKs are, or how they cannot win.  Perhaps this is because they can beat GKs or at least play a competitve game against them, or maybe because before GKs IG were the 400 pound gorilla in the room that everyone hated.  I really don't know.

What I do know is that the games I've played against IG with GKs are some of my most memorable 40k games.  They are what all 40k games should be, close, competitive, slugfests that come down to who makes the least mistakes/or best moves during the game.  I wish all codices were more balanced against each other.  Perhaps my biggest qualm with 40k as it stands now is that some codices stand very little chance against others simply due to a player's list.  For example Dark Eldar, pound pretty much any foot list (I'm looking at you Tyranids and Daemons) so badly that the game is not really even fun for the winner, let alone the loser.  I think matchup issues like this are bad for the game and are something GW needs to consider more when they create codices.  Ideal like all poinsoned weapons or force weapons are cool when it comes down to fluff, but in the game they end up being far too powerful against certain army builds.