ninjablade can be calibrated to Rec709, has accurate scopes and waveforms AC7 does not. I sold my AC7 for that reason alone the recording was just a plus.
AC7 (LCD version) always had a warmer/yellow tint I couldn't dial out completely. The ninja blade currently has some issues with recording images with pulldown. I find the focus and exposure tools on the blade better and more user friendly to use.
+1 on Nate's comment about the AC7 being perhaps just a gnat's too warm.
I've not actually used the AC7 since getting the Ninja Blade - faff factor, etc.
I had to have the AC7 on most shoots because the C100 screen was frighteningly bad for clients. Now, it only comes out when the client pays for it. Meanwhile, in PAL-land, the 2:2 thing is (in my best Wallace & Grommit manner) 'workroundable' and I still believe the bedtime story that it will be fixed soon.