My sims were very difficult on FAR and I ended up skipping one whole tab and a research question due to time.  The research question was literally a paragraph long, dealt with a complicated subject, and it would have taken me 15-20 minutes just to find the right standard.

My answers on the rest of the sims felt half-assed at best.  They were on the most complicated subjects and required lots of steps.

It's a good thing if your MCQs get more difficult.  I noticed that mine did.  One mistake I made was that I had a lot of time left over after the first testlet.  So I went back and skimmed over my answers for about 15 minutes.  I didn't change anything.  I could have used that extra 15 minutes to do that tab I didn't have time for.