Some thoughts after wearing a helmet indoors at my desk all week (can't return it after road use):
Schuberth C3 Pro: breaks in nicely
The Schuberth is actually breaking in pretty well. The first two days I got the same forehead pressure as my old helmet after an hour. But after 5 hours on my head it's gone. I'm probably up to 12 hours now and it's as comfortable at 1 hour as 3 hours. I still feel the helmet and expect to until days of break in, but it feels good now. Not perfect, but pretty good.
Arai Signet-Q: the long oval
I tracked down a store with Arai Signet-Q, which is supposed to be the longest long oval. The upper head fit was excellent. I could press hard toward my face simulating wind, and didn't feel any pressure focused on my forehead. It was distributed evenly across the padding, so that's legit possible.
Press testing the Shoei Neotec vs Schuberth
I repeated the face press test with Shoei Neotec in the store. The shape is closer to the Schuberth but the forehead padding is so thin already that it was immediately irritating with wind pressure. When I got home, I press tested the Schuberth and surprisingly it's fine. The forehead padding is thick but has just the right amount of flex for me. I could press really hard on the chin bar and forehead, and before the forehead fully compresses it's being distributed evenly across my brow and cheeks.
In theory I should buy the Arai Signet Q because it's the perfect crown fit, but I'm going to keep the Schuberth for three reasons:
1. I rarely ride over 2 hours and 80% of my riding is 30-50 mph. Riding on the highway sucks, destroys your ears, and feels like a death trap. I'm pretty sure I could wear the Schuberth all day with a lunch stop and never feel bad. 5 hours straight at 75 mph... maybe not, but really I wouldn't do that ride. I'd take the slow roads or drive a car.
2. I know Arai is a premium brand, but it just feels cheap vs the Schuberth. Probably the demo model was abused to death, but still wasn't impressed (aside from crown fit). The lining looks like a 1995 Ford Taurus carpet (fuzzy loose fibers). It feels fine on my skin, but it just looks/feels inferior in your hands. The visor lock is hard as a rock and detents felt non-existent. Racers probably like that, but for the street riding it feels like the visor is either locked or open — and that's it. The cheek pads have multiple density foam so the jaw line stays stiff but the cheek feels very compressible. For the proper shell size, it made it feel very loose laterally. I could squish it 1-2cm just by pressing sideways on the helmet. The in-store model was a Pro with the exterior sun shield and that felt like total crap. Got jammed up and had poor sun coverage. I did like the venting, but the whole package just didn't feel like a $600 helmet.
By comparison the Schuberth just spoils you. After trying a dozen helmets from the top brands, nobody is close to their liner feeling. It's this coolmax/thermocool blend that feels like somebody turned suede into a technical fabric. It's just butter soft. The padding feels even density all around, but definitely encompasses your head with the thick neckroll. I don't mind that because it feels secure and "there" without being loose or tight. I love their outer visor because it has finger tabs on both sides, and it's the only helmet I tried that (a) can be opened one-handed (b) can switch detents without abrupt skips (c) doesn't twist like crazy. The inner sun visor I really liked in the store. It felt smooth and they met some intense Australian optical standard with it. My specific unit has a stiff opening and has an annoying wavy distortion right in my eye line. So I need to exchange it regardless. The venting is limited compared to full face helmets. Probably it's mostly to minimize noise. For $770 it feels like you're getting a lot more helmet.
I'd be hard pressed to say the Arai was significantly more refined than a $250 Scorpion. The shape was right, but everything else felt off to me. If Schuberth does a C4 with multiple head shapes I think they'd kill it.
3. Better options for communication systems on the Schuberth. Their SRC is apparently crap, so I bought a Sena 10u at the same time (haven't opened) because it has that OEM-style integration. There's supposedly a fit problem with the L and smaller shells (I'm a large). Waiting for some feedback on ADV Rider from other owners of this pairing.
So yeah, I kind of backtracked on the "all day comfort" aspect, but I believe it'd be possible with the perfect shell fit now. For my riding style I'm happier with quality feel wherever I touch it. The Schuberth break in changed my mind and I'm glad I lived in the helmet for a week. If it hadn't softed up I wouldn't have kept it.
If you're on the edge in the shop, buy one, bring it home, and wear it whenever your face is clean. I think that's the only way to get a real assessment if it's your 1st/2nd helmet. Then hopefully you can stick to a model line.