Anyway, I had a Nolan N-104 for some time. Used it extensively in the heat of Turkey and the cold of Germany. Never misted up, but very noisy. Very comfortable liner, but the quality of the rest was utter shite. I had the locking mechanism replaced when the Bowden cables stretched too much to release! Also the lifting lever on the front snapped off. I have to say though that the Nolan customer service was excellent. Bits sent within a week and FOC. However the excellent service wouldn't be required if the thing had been designed properly in the first place.
The other annoying problem, actually shared with my Neotec, is a drought that blows up my schnozzle and tickles my nose hairs, meaning I have to scratch it madly every few seconds!
As to my current Neotec: Quieter than my Nolan, but not as comfy to wear. Build quality is much better though. Doesn't seem to mist up, and has a nice flip mechanism. Sun visor is good too. Only problem is the draught mentioned above.
I tried on the Schuberth C3/Pro & BMW System and much as much as I wanted to like them, my head just didn't fit...
I also had a German (Germot)flip-front, which although it was cheap, did work very well. It just wasn't very quiet.
A word on comms too, for those that use them. I tried to get several of the known brands to fit on my Nolan, but they'd cleverly designed it to only fit their own, very neat, system...which cost an arm and several other body parts. My Neotec has a Sena SMH-10 bolted to the side and seems to work very well...
Final point: As several have pointed out, a helmet may work really well on one bike, and be bloody noisy on another due to screens/fairings etc., Mine were tested on the AT Classic
, 1100RT and my current Varadero. I experimented with screens on both my AT and Vara, which showed up the big differences a bigger/smaller screen made noise-wise. The RT seemed to be pretty good without buggering about with it.