Well, your "facts" aren't that hot either
I have actually had several (at least 5) bikes with internal gears. I haven't owned a Nexus 8 myself, but know several that does. 36% of the population in Copenhagen Denmark commute to work on bikes, and eg. one of the bridges I use is crossed by more than 65.000 cyclist a day (even counted in rainy and cold October), and since the majority of bikes sold here in Denmark have internal gears, it is easy to gain some fairly direct knowledge on how a hub like Nexus 8 performes if one ask enough people.
As I wrote, many people are happy with their Shimano Nexus 8 hub, especially those who doesn't ride that many miles per day, or have several bikes (spreads the load). Some high milage commuters, like my colleague, hasn't been that impressed with their quality.
Of course, this is "just" opinions, but what else do you expect on a web board? Scientific reports?

Regarding internal hubs in generel, then it is just a basic scientific fact that they never will be as effective as derailleurs, there will always be some drag.
It is not a scientific fact that internal gear hubs weigh and cost more, than comparable priced derailleur systems, though I am convinced that it is so. A Shimano Ultegra hub+105 derailleur+Tiagra cassette (you probably want 9 speed) will probably be cheaper than a Nexus 8. (the actual pricing is left as an exercise for the reader).

I think it is pretty straightforward that internal gear hubs are inferior to derailleur systems in most (all?) aspects. Some people seem to think that internal gear hubs are maintenance free, but I really think that that's only a myth. If you clock a lot of bad weather miles on an internal gear hub, you better service it once in a while, or risk destroying it.

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Regards