I fly this specific route a fair bit... I'd jump on this deal. Your chances of finding a better deal in J are pretty slim.
That being said, you could always buy a ticket in coach, and try to upgrade for $$$. My wife has done this numerous times and been able to upgrade for anywhere between $0-$1,000.
I highly doubt that someone will be sitting in a middle seat in coach. These flights are not full at all, according to my family and friends who work for AF.