It was for me, to a degree. I finished every block but sometimes didn't have time to go back and check all my marked questions. I attribute it to the stressful situation/having to reread questions a few times. In one block I also seemed to get an inordinate amount of "long" questions (the ones where they give you a lot of blood variables...CBC, electrolytes, coags, etc.) which takes a while to look up all the normal values.
I was finishing Q-Bank blocks in about 40-45 mins but took 55-60 mins to finish blocks on the actual exam.