GMAT Strategy

I took the Kaplan online course this summer (June/July) and then studied using the Kaplan online software and CATS, the OG 12 and GMAT Prep in August while working full-time and having the usual busy life. My score history is as follows:
-Kaplan Diag: 530 (didn't finish last 7 math questions)
-Kaplan Cat 1: 530
-Kaplan Cat 3: 570
-GMAT Prep 1: 600 (Q33 and V40)
-Kaplan Cat 4:630
-Kaplan Cat 5: 630
-GMAT Prep 2: 580 (completely distracted test environment)
-Real GMAT 9/9/11: 620 (Q42, V34)

I really needed to get a 650. I could take the second test again by early November and still be OK application wise. My access to Kaplan resources expires tomorrow. My question is, should I do another study course--like Knewton? Or, should I just use the OG 12 and rework through those problems and the GMAT prep. Keeping in mind that I have a full time job and a young child so I can only devote time to studying at night and on weekends.

I appreciate your thoughts.

If you are targeting for 650. You are already close. Its not about test prep companies. Its about how much you put in effort to improve. I guess the test prep companies will be starting from scratch again which isn't necessary for your case. If you can do it all by yourself well and good. Try to find which section you are good at, one in quant and one in verbal. Solve more problems in that, review a lot and increase your hit rate.

V34 is in 70th percentile. Q42 is around 65 percentile. Your 1st gmat prep indicates your V40. Whichever section you find it comfortable. Start with one and go ahead. Check the split up of Kaplan Cats and see which section you were scoring high but dropped in the real test. You can improve easily in that section. AFAIK quants is easier to improve in short time. Its just application of right rules and formulas. All you need to do is improve on that. Geometry, probability, combinometrics and number properties - If you concentrate on these more you can move it upto 48. It is equally important to concentrate on other sections as well. So solve problems in all sections, keep reviewing whatever you know already but give more time to which you section you want to improve.

That's what I was thinking. I don't want to waste time with test format and so forth since I'm familiar with that. In all my practice tests I scored significantly higher in verbal. Usually around 80 or 90 percentile. I scored consistently lower in math and so for the past month I focussed entirely on math. Thus, when I took the real GMAT my math score was the highest it has been and I think my verbal was below my ability level. I'm not familiar with the acronym AFAIK, could you spell that out? Besides working with the OG book, would it be wise to invest in another book if I decide to study on my own this time?

I appreciate your time.

Thanks

Sorry AFAIK - As Far As I Know . It depends on which section you are willing to work on.

Manhattan is good for quant basics and foundation, SC.
Heard Kaplan is good as well for quant. But i have no idea about kaplan.
Try downloading 300 best gmat quant/CR problems from BTG forum. You will find it useful with lot of tough questions with good explanations from experts.
Must GMAT problems/Jeff sackman's challenge. Must gmat problems is compilation of tough OG problems so if you are going to take a GMAT prep then more chances for you to see repeated questions.

Powerscore CR Bible for CR - I found it useful though I use mixed approach.
RC99 - best for RCs

Apart from RC99 and the 300 best gmat cr problems i don't have any suggestions for good materials in verbal as available for quants. Other people might throw some light on this.