As I was reading through the rulebook last night and tonight, the one thing that stuck out more then anything was the change to the jink rule.
In 6th, skimmers, bikes and jetbikes just got a cover save for moving. Flyers could choose to evade for a cover save.
Now, in 7th all of them must choose to jink or not. This is done *before* to-hit rolls are even made. If you choose to jink (for an improved 4+ cover save instead of 6th's 5+), then you can only snapshot the next turn.
This is a big difference and really challenges the effectiveness of Wave Serpents, Hammerheads, and bikes of all kinds. I know I loved giving my Hammerhead and Skyray a 4+ cover save (disruption pods) just for moving a nudge.
I don't think this will curb the enthusiasm for White Scars bike armies much at all, but any decent amount of AP3+ shooting will mean making a hard choice.
It will also take a smidgen of survivability away from Seer Council. Not much, but that means any decent amount of AP2 shooting is a lot more dangerous then it once was.
Waveserpents though will pay the heaviest price IMO. They will really need to make hard choices between saves and shooting, especially at the 36" range of scatterlasers. Hanging back may fix that but it means losing the twin-link on the serpent shield.
For Orks, it means the Dakkajet may actually gain a bit of survivability, but Defkoptas loose some. I'm still a fan of them, and despite the change to jink I think they have a nice role to play in 7th.
More on that to come.