hey there, ry,
I want to chime in and let you know some important changes to the GMAT. If you decide to take it now and "settle" with a score, know that by June 4 of 2012, the GMAT is going to get a makeover. What does this mean? Well, it's going to be different. How different? I don't think anyone can tell you that yet (but you can google some of the changes to see it). My point is that if you're scoring a 750 right now, I'd go ahead and take it. However, if you score a score that you're happy with right now (i.e. 660), but ultimately decide to retake it later on, the test is going to be dramatically different. This means that all the preparation you had put in would be "semi-wasted". In addition to the dramatic shift in GMAT testing in 2012, keep in mind that your score is good for only 5 years. If you're planning to apply in 4 or 5 years, you may be pushing yourself to the limit. What happens if you don't get in in 4 or 5 years? Your test would be voided once it passes the 5-year date. Anyway, you should keep all of these in the back of your head when you make your decision.
Cheers!