I know personally for a relatively short flight I would definately try the new J. Think what you would be missing.. An F lounge which IMO is fairly poor and not much better than the C lounge, an old semi-reclining regional seat that has seen better days, a quality meal (but you can BTC in C anyway so no problem there) and a lot of trouble ringing up the ICC and messing about.

New J, all in all would be a much better option. The only thing that you will miss is the F service but hey this is SQ, it's service in C beats most airlines in F!