Began studying 2 mo's out, usually during the day on down time. Found comquest to be superior with the question quality; however, combank was only marginally worse with question quality, but their mobile app was excellent and did far more of their questions as a result.
Did Comquest, Combank, and used MTB for reference:
Comquest: 71%, first time through
Combank: 70%, first time through
COMLEX I and II: 550
Step III: 592
I would not push my exam for fear of the new section, just take it and be done with it. There is no way to be better prepared for the CDM.