I'm planning to enroll in a class in December and January and take the test in February.
One disadvantage of Feb is that it's an undisclosed test. This means you get very little feedback. So it's great if you do well. But if you don't and would like to know more as you plan to re-test, you are out of luck. Many LSDers have expressed frustration about the limited feedback you get for the Feb test. Most who take the Feb test and don’t do well swear NEVER to take a Feb LSAT again. Of course, none of this matters if you do well and don’t have to look back.