The first thing that stuck me was how handy it is to actually have the cards and not needing to write stuff down is a huge help to speeding up our game (something we struggle with!). There seemed to be a fair amount of repetition in the deck, but found the discard function helped with this.
There were only a couple of cards that we didn't have any use for, I think I drew one that had something about psykers, the council of Nikea put the dampeners on that one. The objectives made the game feel very up in the air, neither of us knowing who was really winning or losing until the roll at the end of turn five. This game was eventually won by Dean, who on his last turn got one that was 'get D3 points if you kill or have killed the warlord'. He then proceeded to double out my Magos with the lascannons off his Storm Eagle, four points in one kill gave him the game!Despite me losing this game was incredible fun, and we'll definitely be using these in many more games. We've got the new Cities of Death Tactical Objectives to try out too that came out in WDW recently. And I've grabbed a few of the datacard sets with each of the 40k releases. There's definite possibility to customise these decks, and in my head I've even started thinking of making my own 30k centric cards!
If you haven't tried them out yet, you definitely should!