There is more information about GACs in post #6 of the disABILITIES FAQs thread. GACs are not really meant to shorten the wait in line, more provide conditions to wait that meets the needs of the person with a disability. Some of the accommodations given for disabilities can actually make the wait longer at times (for waiting in a different place).
Many people have posted that using a touring plan like TourGuide Mike or RideMax actually was more helpful than a GAC. Even during very busy times - like Spring break, Christmas and Easter, there are parks that are quieter some days than others and parts of those parks that are quieter than others. For example, if you go to MK almost any day at opening, you will be likely to get on many attractions without waiting more than the time it takes you to walk thru the lines. And, if you go to Epcot in mid-morning, you will find lines of over 1 hour for Spaceship Earth; by mid or late afternoon, you can walk onto Spaceship Earth without a wait at all. Touring plans like TourGuide Mike can help you to know where to go and when to find the smallest crowds and shortest waits. It is much more consistent than a GAC because with a GAC you never know what you will be told to do - the exact what depends on things like staff, how many other guests with special needs are waiting, etc.
If you are planning to go in February again, that is usually a very slow time - except for the time around Presidents Day (I think the third Monday in Feb).