I checked my 6s+ today, and found that in fact it does have a very faint hiss, but it is much quieter than the 7+. If I had to guess, I'd say the 6s+ sound is 5-10X louder.
I never would have noticed it on the 6s+ if I hadn't been looking for it. With the 7+, I checked immediately after receiving it, and I am confident that I would have eventually noticed even if it was not for this thread.
I suppose this leads to the question of "what level of hiss is tolerable". I would of course prefer for it to be at the same level as the 6s+ or quieter, but it may ultimately be a problem of "when you have a processor this fast, you have no choice but to have a hiss".
I never would have noticed it on the 6s+ if I hadn't been looking for it. With the 7+, I checked immediately after receiving it, and I am confident that I would have eventually noticed even if it was not for this thread.
I suppose this leads to the question of "what level of hiss is tolerable". I would of course prefer for it to be at the same level as the 6s+ or quieter, but it may ultimately be a problem of "when you have a processor this fast, you have no choice but to have a hiss".