Mob Rule and bosspoles

If they had simply left mob rule alone, this codex would be a success.  Instead (like instinctive behaviour or daemonic instability) GW seems to think assault is too over powered and needs some limiting factor.  Nothing comes to mind specifically for shooting armies as a limiting factor.  Gets hot (especially on a marine) doesn't count.  Morale affects Orks just as much (though not Tyranids and Daemons except in the cases of ID and DI).

It's not the fact that you kill yourself (which also sucks), but that morale is so easy to fail.  Nobs don't even give out Ld8 like a proper upgrade character.  Outside of HQs (or Lords of War) you can't even get Ld8.  Hell, some of the HQs are still Ld7.  This means you fail tests all the time forcing you to roll on the .

Cyborks

The leadership bonus is also gone.  For those that don't remember, you could substitute your leadership for the number of orks in your unit and at 11 and above you were fearless.  Fearless and Ld10, don't forget.  Leadership tests or attacks that wound on leadership are now more deadly.  Psychic Shriek is very common now and extremely deadly to Nobz and meaganobz who cannot get an invuln.  Fear is a leadership test, not morale, so mob rule doesn't help you here at all.  Abyssal staves formally wounded on 6s, now wound on 2s.

Tank shocks are a very valid tactic against orks.  Make them take a Ld test on 7, if they pass they're bunched up, if they fail they either kill some of their own guys and then bunch up or kill some of their own guys and fall back.

Unlike marines, if you fall back you don't automatically regroup.  If you are above 25% of your starting unit size, it's just a normal leadership (usually on 7)  test not a morale test so mob rule doesn't help you here.  If you're below 25% you can only recover on double 1s.  Even if you do recover, you can only move 3", cannot run, can only shoot snap shots, and cannot assault.  If you end  up failing, it will be 2 turns before you're back where you started.  This hurts a lot.

Bosspoles abound

 Just as big of a kick in the nuts was the change to bosspole.  If BPs allowed a morale reroll before mob rule that would be helpful.  Unfortunately, it only allows you reroll the mob rule table.  I'm not sure it is always worth it now.  It does let you reroll the 1 result on the chart so if you're not in combat you can still pass the morale check.

The bosspole does help you if you lose an assault.  For instance if you lose an assault by 5 to take you from 14 guys to 9, you would have been testing leadership on a 4.  Even with a reroll you only had a 30% chance to pass.  Now, if you fail you roll on the mob rule table, re-roll to try for a 1-3 result giving you a 75% chance of staying in combat (at the cost of D6 str4 hits).

Luckily, 7th seems to favor MSU.  I think this may be the way to go.  Make your opponents shoot grots and put your points into a lot of small units that give you tactical flexibility.  Especially if your run multiple CADs.