i was in both side of the boat before. starhub is a lot more stable. as i am not a heavy download user, i merely use to play some light games, i am more concern with stability.
if you are living in old estate, don't go for singnet. the connection tends to keep disconnecting and they will say its not their fault. ITS YOUR LINE THAT IS OLD. this is the bloody excuse i keep getting whenever i get dc. when asked isn't the line belong to singnet, they will start throwing smoke screen.
after switching to starhub, except once in a few blue moon maintenance conducted without any warning at late midnight. i do not have much issue with stability. singnet go fucking eat shit