I have done some GMATClub's Quant tests. They are really good and I recommend them.
My scores are not so much consistent, as sometimes my percentile range from 7 to 60 (two times each).
I was looking at what happened each time and I realized when I scored low, I got stuck in some questions in about 5 to 7 minutes (I know, it is too much).
But in the tests that I did not score pretty good, I spent more time than I should in some questions (about 3 to 4 minutes), but I realized that I overcame it with some questions that I did too shortly (and correctly). Something about 40 to 50 seconds, especially DS problems.
I know I should spend less time in some questions, but my question is: do you guys have/had the same experience with some "too short" questions in order to overcome some longer questions?