The best resource for Quant

The best tools to master GMAT-specific math skills ... Without a doubt, the math tests here were the best tools to improve my math skills.
The questions are hard and will prepare you mentally for any kind of questions that you will be facing on the real GMAT.
The algorithm seems a close match with GMAT prep and most importantly the solution to the 700+ questions are amazing. I highly recommend it to ANYONE studying for the GMAT. Expect at least +2 point in real scale quant grade vs GMATClub.
Always read Bunuel's solution techniques even on questions you got right because he will teach you the tricks to solve the questions faster.

To improve, I suggest to increase the number of Verbal tests. It is really important as it's a big selling point to the non native speaking GMAT takers.

Thank you!