KInG wrote: They would have a field day shooting these fellas to bits before they could even strike or return fire.

They go through a breakdown of
GK in 6th here
http://www.3plusplus.net/2013/05/greyknightsreview1/ and in subsequent articles..
http://www.3plusplus.net/2013/05/grey-k ... s-unlocks/http://www.3plusplus.net/2013/05/grey-k ... -henchmen/http://www.3plusplus.net/2013/06/grey-k ... haracters/TL:DR
6th ed on the surface hasn't been kind (e.g. those weakass pillbox guard mech spam everyone ran as default tactic in 5th are bogged down and being immune to suppression fire in a tank isn't what it used to be (woo 6th ed has forced a slight change in playstyle).. force swords don't rape face.. (who sent terminators against terminators anyway) and they don't get the silly awesome battle brothers with everyone else that astrates get..(but they can sit alongside them as seperates)
But they default have access to divination, purifiers are still the sexy, you must remember their bortherhood mastery for deny the witch (1/3rd ignore whilst everyone else just has to suck it up and get raped by the flying circus) and before that especially with a psfleman advanding in your ranks any lev10 sorceror targeting your guys counts as being leadership6 for trying to get them in the first place.. (its the new/ old runes of warding)..
Take their good stuff, grenades cheap hq and termies (I think I was the only person this time last year field testing them as the only allies permissible already writing off DA termies as potential future allies), or unlock expensive hqs and better troops.. and take something that fills the holes (in my mind some kind of alpha strike DA cheap 5 man scoring missiles etc vindicators and some infravisors to get some first shots offa quadlauncher)
Guard players have upped and quit due to falling off the top slot..so the number of 1000:1 model counts you'll face are much less which is your big downside.
Re taking a jumping monstrous creature horde with more jumping troops.. of course you'll get shot to crap.. thats the point of an assault army.. you lose 1/2th your army getting there..Then the other half win you the battle
either;
a) suck it up
b) take a hybrid force where you shoot back (you faced my bloodhammer with its zillion missiles as well as assault swarm?)
c) don't try to do assault (I have one friend who still insists any assualt phase, any movement anything.. beyond trench warfare shooting phase is beardy.. he plays the wrong sort of games

)