I have been finding that in this edition that Ork MSU's are the way to go. Since we have no armor save, lot "I" and are bad shots the mob is starting to be a thing of the past. The new "mob rule" really beats down your boys, sometimes causing more casualties than the initial shooting/CC that caused the LD check.
So, to counter this effect, I have gone with more vehicles and less boys. My new "normal" is now a ten boy squad that acts like a nob delivery system (in a truck of course) and I now take a minimum of seven such squads. I also take a warboss now rather than two big meks with KFF, and one truck load of boys without the nob to act as a warboss delivery system. Lots of buggies and planes since vehicles don't take LD tests and can hold objectives (well, not the planes) unless there are actual enemy troop choices on the objective. (troops trump other units)
What this does is give the enemy too many things to shoot at, so I still have more units left at the end of the game than my opponent even when I have lost over half my army.
I see by your experience that storm boys are still not the unit that we want it to be, even with cheaper points cost. For those who haven't heard my rants before the storm boys are the only ork unit I have ever got rid of as they way under perform consistently. Great looking models, poor excuse of a unit (IMO).
Glad to see your back in the saddle, with a little list tweaking you may actually be able to win a game. I myself have won only three games since the ork codex came out. Two were very close calls (a single dice roll), and one was by a VP that I earned as I played to the cards rather than my usual krump everything strategies. Before my almost winning streak I was consistently getting tabled, then with my brilliant (stolen from my eldar days) MSU tactic I have started to climb back into the being challenging again.
I may even start posting batreps again now that I almost have remastered my orks. Now, I am still playing speed freaks, so maybe you kan wall types might have a better result with bigger units, but as for me, the MSU is the way to go, especially when playing for objectives.