GMAT Strategy

I'm taking the exam on 1/23, and I started studying about two weeks ago. Here has been my score breakdown so far:

GMATPrep - 730 Q47, V44
MGMAT - 720 Q44, V45
MGMAT - 690 Q48, V36
Kaplan - 670 Q45, V40

As you can imagine, it is somewhat disheartening to be trending downward in my practice tests, especially starting at a 730. I have been practicing a mix of quantitative and verbal each day, with some writing practice mixed in. Has anybody experienced this downward trend/have a possible explanation? I know there are theories on the accuracy of Kaplan and MGMAT, but I don't want to attribute my downward scores to that.

In Quantitative, I seem to be mostly missing DS questions, which is what I have been focusing on in my practices. On the verbal side, CR and SC seem to be my weak points. Any suggestions on a plan of attack to bump my score back up and regain some lost confidence?

I wouldn't take the Kaplan score seriously at all. With the MGMAT scores. They say that there is a 50 point standard deviation between their scores and what you can expect on the real thing. Since GMAT prep is based on past GMAT questions, the 730 is your most accurate score Their scores have a 30 point standard deviation, so on test day, unless you're the type to get really nervous and you allow that to affect your performance, you should score no lower than a 700. Just use the other test as practice and for your last practice CAT use the GMAT prep test.