Hey, acrowson-
That is a lot of hours- at Knewton, we recommend about 6-8 hours a week for the two months before the test, which is the period you're in now. Your 20+ hours/week may very well burn you out rather than prepare you for the test. We know you're aiming for a serious score jump, and that's great (and certainly achievable), but moderation is always best.
For more details about hours of study, and how to focus your time to study SMARTER, not HARDER, check out this blog piece by our faculty manager and superstar GMAT teacher, Dave Ingber:
https://www.beatthegmat.com/mba/2010/04/ ... r-the-gmat
Of course, the Knewton course was designed to help students hit their goal scores while maintaining a busy work schedule. You can trust our course to guide your study schedule. Meanwhile, if it makes you comfortable, keep up the hard work, but if you feel yourself burning out, make sure to make adjustments!
Best of luck!
Alex
Alex Sarlin
Verbal Lead
Knewton