It's not the first time that a Seasonic PSU impresses me, but in this case I was way over the moon when I finished all tests. X-460FL is a terrific PSU in every aspect. Even though it has no fan, it managed to easily handle full power even when I cranked up the heat inside the hot box. On top of that it showed great efficiency and pretty tight voltage regulation on all significant rails. Actually Seasonic's claims that all rails are within 3% voltage regulation proved to be solid. As for ripple suppression again Seasonic proved that it has the knowledge to flatten all DC outputs and make ripple vanish.
To sum up, if you really hate noise and you don't have a problem to spend some money on a really worthy PSU then you should go out and get the X-460FL. The only restriction of this PSU is the relatively limited capacity that is enough to power only a single graphics card, but on the other hand fanless PSUs are not intended for systems with two or three VGAs, but for small ones like HTPCs where output noise is the primary concern. Finally, at the time of writing, and to the best of my knowledge X-400FL and X-460FL are the only 80Plus Gold efficiency fanless PSUs available on the market.