The quant on gmatclub tests is top-notch. It prepares you for 700 level questions.The timer in the practice questions is an excellent tool in itself. What i learnt most were from the explanantions given by the gmatclub members.Explanations and ''less time consuming approaches'' are very helpful in learning.
the question set in itself covers all the topics and is more than enough for one to prepare. I was scoring in the range of 46-49 and i could immediately where my gaps were.
Though i didnt use the error log feature recommended by everyone..i still believe that the errorlog and the timer are two features which are immensely helpful
Overall, GMAT club is the destination for all GMAT aspirants both first-timers and repeaters. It is not just recommended...but given - a must use to score 700+