Deads and Angry shrugs

Wednesday was peak night for our 4 week conventional DL cycle.
295 X 8
365 X 6
425 X 5
495 X 3
555 X 2
585 X 1
620 X 1
650 X 1 (used the hook grip for this, but it didn't hold that long at the top so it was a sucky soft lockout)
665 X nope.  Flew off the floor and up to about 2" short of lockout and had same issue with the hook grip.
675 X nope.  Again, the weight moved fast off the floor, but was not my grip this time, it was my sucky lockout.  I have had this same issue with conventional and sometimes Sumo deads.  I have to learn to push my glutes through and start in a better position.
Weighted sit ups with bar lying on the floor: 95 lbs X 3 sets of 10
shugs: 225 X 10, 315 X 10, 405 X 2 sets of 10.  Spud called these angry shrugs, because I didn't really need to do them, but I had to do something somewhat violent because I was mad because my DL night sucked.
Things to work on for the dead:  Glute strength/hip extension, Grip.  Plan to fix them: glute hams, barbell bridges, farmer walks, wheelbarrow.  It starts Saturday.