I recently came across these resources and I have added them to the list of my study materials. One is GMATFocus. This is a Diagnostic test (quant only, NO verbal) consisting of 24 questions in quant. The question set is assembled by the best source of GMAT questions - GMAC, the people who conduct the real thing... It costs $25 dollars for one test and you could buy a set of 3 tests for $65. I agree is expensive but i decided to get the set of 3. In case you are debating on whether to buy it, then here is my reasoning.. Think of it as an investment. Your are going to spend around $50k to $70k on your business school, loose 1-2yrs of pay, and spend a lot in living costs while doing your MBA. If you are determined to spend this amount to obtain your mba then i think $65 would be like a drop in the ocean but it would be well worth the money spent. You get 72 new original GMAT questions to work on. Moreover, GMATFocus, unlike GMATPrep, gives you an indepth analysis at the end of each diagnostic test and tells you your exact weakness so that you can concentrate on that part. Now enough of my review and here are some review on it by some experts - Manhattan GMAT review and Jeff Sackmann's review.
The second one is the Manhattan GMAT's flash card set. Amazing set of flash cards covering various sections of quant such as Number properties, eqns, decimals, percentages, geometry, word problems etc., and Secntence correction. There are a total of 202 flash cards and the best part is its Free!!!!!!!! Here is the link - Manhattan GMAT flash cards.
I'm planning to take one diagnostic test from GMATFocus today. I will update this post with my views after taking the test.
Update: I just took the first GMATFocus test and here is my review - The first thing that comes to my mind is that it was tougher than the GMATPrep, and definitely tougher than most problems in OG11. The problems that i encountered today needed a lot of calculations. GMAT questions are supposed to be solved in less than 3 steps, but the answer explanations of some of the questions in GMATFocus involved 5 to 10 steps. For eg. one problem required to form 2 different equations, then apply a condition to one and then solve the equations to get the value for a variable and then substitute that in the eqn. to get the other value. It was easy but took me almost 160-180 secs. I got a question on Permutation and i had not reviewed this section at all.
The result is presented in a detailed fashion showing you your estimated scaled GMAT quant score, section-wise and topic-wise strike rate, time taken to solve right answers and wrong answers, number of them guessed etc etc. What i didn't like was their overall scaled score prediction. They predicted my score to be within 40 - 47 with 80% confidence. Well, i guess after completing all the three tests may be i'll get some insight to where i stand!!!
So overall the experience was good, and it was a very good practice of some new questions.
Verdict - Recommended.