I recently flew SQ C NRT-SIN on the A380 and TG F BKK-NRT also on the A380, and TG F was definitely superior in both the service and the seat.

I enjoyed both experiences but I found SQ service to be a bit impersonal, while TG was much more friendly. I found aspects of the SQ C seat to be a bit weird, such as the droopy headrest that does not seem to be adjustable, the flimsy footrest, the height of the seat after being converted to a bed, the poor resolution on the IFE. TG F on the A380 is a solid First Class seat and bed that comes with a personal closet and a full footrest and nice amenity kit (Rimowa).

To top it all off, the F lounge and spa experience at BKK is a treat!