I'm not positive that a picoPSU+brick is really more efficient. The efficiency o the brick itself is critical, and even level V efficiency in bricks doesn't guarantee anything like 90% efficiency at <50W load. See here for the formulas to calculate efficiency requirements for Level V bricks
(PDF) -- you need some math!
Perhaps the picoPSU+brick gains the efficiency edge when power draw drops to 40W or so, again depending on the brick. But at that point, the actual power differences -- not % but watts -- become tiny even with fairly big % efficiency differences, so it's increasingly more trivial as the power levels goes down.
Plus, efficiency is just one parameter of many... including convenience, noise, compatibility, price, versatility, other electrical performance factors.
There's no way any picoPSU+brick can match the other electrical performance factors -- ripple & noise, voltage regulation (esp the 12V rail!!!), etc. The G360 will give cleaner, more precise power under a huge range of conditions that a picoPSU+brick simply cannot. Unless you pay through the nose for the brick... because 12V regulation is totally up to the brick.
For a mini PC, yes, the picoPSU+brick is great. But for mATX or small ATX case, I'd take the G360 hands down. What you get for the price is unmatched right now.
As for the Nexus 430 -- it is a super quiet PSU, but middling in every other way when I reviewed it 3 years ago. Today, it's history, afai am concerned. I never did think it was well built or designed, I think Nexus went out on a limb with a super quiet fan in an average PSU, jacked up the price, and kept their fingers crossed they wouldn't have to replace too many of them in the long run. It may have worked for them probably because the only folks buying them were silencers with minimalist rigs. The G360 kills it in every way but noise, and if your typical/max load is <200W in a good modern case, that noise difference is inaudible: 11 dBA vs 13 dBA -- you really think you can hear that in your room with other gear and things going on? Forget the Nexus 430, it's history.