I'm done! I took the GMAT today and scored 730. I got a 48 in Quant, which was higher than all of my practice tests, and a 42 in Verbal, which was lower than most. I'm not taking this thing EVER again!

I used the Guided Self Study from MGMAT, which was extremely helpful. I needed the structure and schedule it provided. The class recordings were pretty useful, and the office hours were very helpful, too.

My practice tests:
MGMAT 1 510 (26Q, 34V)
MGMAT 2 640 (43Q, 35V)
MGMAT 3 720 (44Q, 45V) *** After this I resolved to only take GMATPrep tests
GMATPrep 1 740 (47Q, 44V)
GMATPrep 2 730 (47Q, 44V)

Some lessons I learned:
-MGMAT is awesome for learning content. Once I was done the MGMAT syllabus, I stuck to the OG-11, and then OG-12 (this was released as I was studying.)
-MGMAT CATs are harder than the real thing for Quant.
-MGMAT verbal sections, specifically the CR and RC, weren't representative of what I saw on the real GMAT or the GMATprep. The logic behind the more difficult CR and RC questions doesn't work a lot of the times.
-MGMAT SC is awesome.
-The GMAT will always feel hard. Thus, I tried not to dwell on how I thought I was doing and just pay attention to doing my best on each questions.
-Use CATs to build stamina. They are not a good way to learn content, though.

I also read debriefs here and on the MGMAT forums for inspiration.

Thanks to all the posters from whom I've benefitted, and thanks to MGMAT!