What's been interesting about this fare is that it was $720 until around January 15 or so, then it went to $870, now it's back down to $620. Looking at the ITN seat maps, the booking does look extremely light. I'm wondering if the fare might drop a little more, or if this is the time to book.

While there are still lots of upgradeable BF seats, if the booking is this light coach might be pretty comfortable.