I'm happy to say, I've basically never flown Business or First. So I don't know what I'm missing. I'm sure it's good, but I deal with Economy for now.
Down the road, when my wife and I travel without the kids someday, we'll be more likely to splurge for First. Two tickets in First on miles is something I can handle; four would be pretty painful.
I do know that the first time I take my wife in First, Coach is done for. So I'm trying to wait it out.