Conclusion:
I test a lot of power supplies here, as you've probably seen, and out of all of them the Seasonic S12II really stood out to me. For not much higher than $100 they offer an incredibly high performing power supply which also has a very high efficiency rating and at the same time they manage to make it so silent that it's quickly becoming a benchmark for other silent power supplies. I personally have no complaints with this power supply and would recommend it without a second thought to anyone building a quality computer system or a silent or home theatre PC. The only thing I'd like to bring up is the fact it isn't modular, although not a big thing for myself, this does seem to be the only common complaint I see about this power supply. All in all, well done Seasonic on a solid product!

Pros:
Excellent performance
Incredibly silent
New 5 year warranty!
Quality construction and electronics
Price
High Efficiency

Cons:
Many would like to see a modular version of the S12II