Ditto. SQ - no doubt.
Last couple of times I've flown Garuda out of Singapore to Jakarta and Bangkok... on the former they were nearly 1 1/2 hours late and on the latter, although Garuda were on time, they had a nosewheel problem upon landing and we had to park 30 minutes on a Taxiway in BKK before being towed to a Parking Area and then bussed to Arrivals... ho-hum..
Most SQ flights on the other hand I can remember very little about - which is just the way it should be. I'd always rather be on time in an Economy Seat than waste time in a Business Seat..
So it comes down to whether the Business Class Gado-Gado is better than the Economy Sate - and is that worth the probability of more hassle vs. less hassle? As 763 jock says ,'No brainer'...