Performance: "Clear advantage" is meant literally. It is clearly measurable that there is an advantage. I'm observing this, not passing judgement. You see a lot of people choosing one waterblock over another because of performance, yet the blocks are mostly very, very close in performance. Also, many people optimize their loops for higher flowrates even though more flow will net you only fractions of degrees in better temperatures after a certain point. In this context, I can imagine that 0.7° is an advantage worth having for some people. Ultimately, that's up to each individual to decide.

Residue: The current sample is a new one and I'm doing a long term test. So just sit back and wait. We'll see if the residue problem is still present. I'm not saying it isn't, I'm just saying we don't know yet.

Why would anyone use it? In my experience, because it looks awesome. I've gotten dozens of e-Mails and PM's since I published the first review, asking about the Nanofluid. Of everyone who wrote, I think no one cared about the performance. They all just wanted cool looking white stuff in their loop.
This is also what I personally like about the NF most (as I stated in the original review).