Hi gmat1212.
Given what you said about taking the class, how you prepared and the results you got, it sounds as if probably you could benefit from making your work more based on your test performance. It's almost as if there has been a divide between your preparation and what you have to do in order to score higher, as if maybe you have focused on learning and applying a bunch of strategies and "covered all the material" without somehow actually connecting what you have been doing directly to making your score increase.
Overall, I think that what you have to do is make more of a point of going over your practice tests and seeing what you have to get better at in order to score 730+. Then seek to directly address what you find.
For instance, to break through in quant, find a type of question you are not that good at and work on only that type until you totally rock at it, whether doing that takes three hours or forty. Then find another type and do the same thing. Each type you do that with is probably good for a point or so higher in the quant section.
I realize that you said that things go well in practice, but something is missing, and going over your tests is the way to figure out what is missing. If actually you are super good at getting answers to all types of quant questions in practice, which does not seem possible given your score level so far, then figure out what else about quant is coming between you and your goal. Is it accuracy? Is it efficiency? Are the questions on the test somehow different from the ones you are using in practice? There is something you can figure out, and, obviously, once you figure out what's going on and address it directly, rather than doing general preparation, your score will go up.
Also, for what it's worth, the quant questions in the Official Guides are mostly easier than the ones you will see if you are scoring at the 700 level. So that difference could be an aspect of what you are experiencing. For some tougher, categorized quant questions, you could set up a free practice account in the GMAT section here,
https://bellcurves.com.
The verbal section requires a somewhat different approach as verbal questions are not quite as categorizable as quant questions are, but still the thing to do to get your verbal score to increase is to figure out from your practice tests what has to change. Don't neglect verbal, by the way. You can get some more points there too.
You'll hit that goal. Just you have to adjust your overall approach so that what you do actually makes your score go up.
