Originally Posted by
rayoflight
For the best business class experience I would recommend flying LHR - SFO on VS, which can be booked as a code share on CO. It involves an extra change of planes to get from VCE to LHR, but you have all you can hope for in long-haul biz class!
Since the OP asked for business class using FB miles, I would be extremely surprised if you could get award seats on VS via a codeshare!
I would definitively not go on DL.