Do you have a link or any more details on this experiment? I'll check out the case, but other details are equally important.
I think there's a misunderstanding: in order to show you some actual data after my words, I made that test right in the morning, and then attached the relevant screenshot to my post (look at traybar clock: I took the shot some minutes before posting).
Anyway, that result was rather obvious, and if you think about, in any kind of CPU air cooler (tower, top-down, whatever) the fan blows through the fins "pour cause" (to be fair, you can have a fan aspiring from the fins just in a push-pull setup, where the fans are two).
The Grandia GD02 is a challenge for sure but I really like the case & I've had it a long time. Others like it are just so ugly! I'm not after perfect cooling, just reliable & as quiet as possible without sacrificing computing performance. Probably a challenge in this case.
If you want to stick with the GD02, there's no problem, it has its own merits.
If you want to stick with a rather useless Core i7, you're welcome (I say "rather useless" because I use a Core i7, and in my experience it's mostly useless under normal home-usage patterns).
Pairing them probably will end up in a hot system, but it should be perfectly safe: more probably you can't have utterly silence with such a setup, at least without running rather hot, but in case it would be your call.
Said that, the Big Shuriken 2 isn't an extremely proficient cooler: it's just one of the best results you can squeeze from a 58mm chunk of metal. More probably that not it's not up to the task to cool a Core i7 quietly under any circumstances (and so it should be for any of the other alternatives which have already been named).
Can the NT01-Pro (with a couple of slow running 80mm fans) be a way to do better?
Well, probably Silverstone didn't think the GD02 for benchmarking or testing (you won't race at Le Mans with a stock Rolls Royce Phantom, I guess) so, whether you should deal with synthetic loads such as "Prime95" or any Linpack based test, IMHO the NT01-Pro won't be able to do better.
On the other hand, in a real life scenario, there are much more chances to work out a perfectly usable rig, which can run enough cool and maybe enough quiet: from the test I read about that cooler, it isn't a stellar performer, but heat-wise it could work slightly better than most of the 60-70mm coolers around.
Summarizing, if you give up the demand to cool that CPU silently with all kinds of load, in real life the only serious drawback I see is that it's a rather expensive option: but it's expensive the GD02 too, isn't it? Have a nice time.