I started preparing for GMAT around August 2020. I used a package from an online prep company. While it was thorough in terms of concepts, I lacked the critical tricks and insights into how GMAT actually works and what exactly it tests. I ended up scoring a 620 in my first attempt due to poor pacing on quant.
After this, I looked around and came across EmpowerGMAT course. After reading a lot of positive stories and using the free trial I decided to go for it. Empower course taught me critical insights into the workings of GMAT. Through their constant encouragement and enforcement in the course videos, Rich and Max force you to change your thinking style. It's one thing hearing that "you have to cut your losses and move on from any question after three minutes and another thing to actually get that into your head as its a "matter of discipline" as Rich says. Overall, I couldn't recommend EmpowerGMAT course enough for anyone looking to cover that last mile between their current score and target score.