I havent really been a regular at this site - due to lack of time I guess, but have found it to be quite inspiring at times. So, heres my two cents.
I didnt go nuts on preparation since I have a full time 10 hr/day job. Might have put in 2 months of mostly weekend work. Frankly speaking I scored above 700 in only one of the GMATPerp tests (i took this a week before the test). I used to find it really difficult to sit for 3 hrs thro the tests at home since I smoke. In fact, I was a little shaken when i took the second GMATPrep test 3 days before the test (this last thursday) and scored a 620.

But, alls well that ends well and I am happy with my score, since I wasnt aiming for 770 anyway.
That said, I would like to re-iterate whats been said in certain other areas of this forum - I think the format of Quant has changed a bit, in that, I didnt get a single probability question. And those dreadful inequality and properties of number questions were plentiful. And it would be lying if I say I didnt feel that I **** up majorly when I was half way thro. But, I took a few deep breaths and told myself that I had cancelled my Netflix subscr. two months back so I could study and hadnt touched alcohol in 3 weeks

and got on with the rest of the test.
In hindsight, GMAT is really a test of endurance, nothing else. It is absolutely imperative that you maintain your calm throughout. My essays were pretty straightforward - "Do you think its an employee's responsibility to stay on top of his technology **** or do you think its the employer's thing to do" . I had a field day here. The other one was better - "Company X a $450 billion market leader in gaming s/w and hardware will perish soon since people will get bored with its product. Company Y a pioneer in the field also suffered the same fate 2 yrs back". The most ridiculous argument and I didnt have trouble in tearing it apart.
As an aside, though I had bought Kaplan and Princeton, I would advice against using those. They are nothing close to the real thing. Total waste of time. The Prin. Verbal workout helped me a little towards the beginning of my prep to get a hang of the test in general. OG is your best bet anyday. Also, I found out that you get diff Quant questions if you d/l the GMATPrep s/w subsequent to your first d/l. But dont expect them to update it everyday
Okay folks I will leave you now as I have to write my app. essays. Btw I am not applying to any full time programs. Langone is my first and last option (wish Columbia had a PT program). Good luck with your GMAT and applications.
Sunandan.