The mtbf(mean time between failure) of the Silverstone is 100,000hours. The Antec is 80,000. Just that the Silverstone is designed to last 20,000 more hours. Its also around 80% effecient (antec 70%). So the Silverstone will waste less power. If you look inside the Silverstone is better designed, better air flow (thats why they last longer). Its just a better PS.
I am not trying to say yours sucks. It dosent, the Antec is ok and the Aspire is ok too, Just the Silverstone is better. And since the PS is the backbone of your comp it should be a good one.
I use a Silverstone Strider 400 to run my rig and I have 4 HDDs,SLI and a Opty 148 with fans and lights too.