When going through the gnar, your feet are always in the sweet spot, no shuffling around and getting into a goofy foot position.
I find this to be the true benefit of clipless pedals. I ride clipless on all my bikes except my DJ for this reason.
Everyone's main concern is getting out of a clipless pedal. Unless your motor skills are severely inhibited, by the second time you ride, this concern will be GONE. Getting in and out of clipless RAPIDLY becomes second nature. Its REALLY easy. You have a ton of time before the Meltdown. If this discussion was happening like a week before the race, I'd recommend staying with what you are comfortable with. However...being that its over a month away, I'd say give the clipless a try. Ride them on the bike path. Practice clipping in and out. You might fall over once or twice, but most people that I've seen do that at extremely low speed...and even then, only once or twice before "getting it." Keep in mind, you can set the tension on most models.
Since you are open to both...bring both sets and a pedal wrench out to the trails. I'd suggest riding to the bottom of Gravity Cavity, turning around, and riding back up with both pairs. See what works for you, and go with it.
And as suggested, try to get more than 35 miles per week...you'll need the fitness as there's a lot of climbing on the Meltdown course.
+1 . Its really not that complicated as everyone makes it out to be. That fear you have of crashing while clipped in is what makes you learn how to unclip real fast.