Sure, I will give the detailed experience after some time as right now busy with app process.
In brief I mugged hard for around 2 months. Materials used are OG12, Verbal Review ,
MGMAT SC, 1000 SC ,RC and CR and SC 700-800 club questions and in office I just used to look at 700 tagged questions in GMAT Club and Manhattan forums.
Test taken after preparation :
OLD GMAT PREP 1 720
OLD GMAT PREP 2 720
NEW GMAT PREP 1 750
NEW GMAT PREP 2 750
MGMAT 1 (Free one) 730
KAPLAN 1 610
KAPLAN 2 630
KAPLAN 3 660
KAPLAN 4 660
Powerprep 1 720
Powerprep 2 750
I have done all these but I will still say that any one preparing for GMAT doesn't require to solve 1000 series as the quality is not that great and it can shake your fundaes also. Also avoid writing Kaplan tests as they don't match actual GMAT test. Believe in GMAT Prep and your score will be in +-30 range of those scores. Whenever write any mock please write with essay sections also as then only you will be prepared for that 4 hour journey. Also I retook each GMAT prep test for around 4-5 times and every time 9-10 new questions were there and of harder level.
Best of luck to everyone preparing for GMAT. May you guys ROCK!