The Akuma Phantom 2 was intended to be a replacement helmet for my Arai Quantum F, so that's my point of comparison. I would likely not have gone looking for a CF helmet in particular, but the photochromoc visor was a great draw to this helmet.
Ok.
Pros: It feels light when it's on my head, and it looks good. I find it is cut in such a way that those quick looks over the shoulder are easier than they were with the Arai. The Arai's chin bar would contact my shoulder when I looked back. As well, the Akuma has a wider field of vision, helping to eliminate blind spots. It has a D-Ring chin strap. It has a more square type D-Ring with teeth in it. I think I would have prefered the traditional smooth rings, but it's ok. Ventilation seems very good, although it's been cool where I live so that's subjective at this point. It does seem like there's a lot of airflow inside the visor, particularly when it's set to the cracked open anti-fog setting. The Akuma has a removeable liner which the Arai did not have. I disagree with reviewers that say the liner is not comfortable. I find soft and the support is good, although the Arai has more padding in it. My helmet came with the SOLFX shield, and I am quite pleased with it. It gets quite dark in bright sunlight, and is clear at night. Compared to my Arai the shield id a pleasure to remove and install. Easy.
Cons? I found the felft chin strap with the D-Rings on it too short by a couple inches. This is an irritation every time I use the helmet. As well, because the strap is too short, I gave up trying to snap the loose end up to it's retainer snap. The top vents whistle when they're open, but I knew that before I bought the helmet. I do get a a very infrequent whistle from the shield, but not a real bother.The tab for lifting the shield is either too small or placed wrong, I have to fumble with it a bit to get the shield up. The helmet de-fogs all right at speed, but fogs up when I stop. I leave the shield open a crack most of the time.An issue that I was unaware of at the time of purchase is that there is no clear shield available. Before someone tells me that the stock shield do that duty, there's two reasons that's not true (1) If you need a replacement the clear shield is cheap, the SOLFX shield is not. (2) The SOLFX shield is never really clear in daylight. I rode in a really dark threatening overcast the other day and the shield was carrying significant tint. Not real dark but I could really see the difference. And if a truck kicks a rock into the center of that stock shield, it has a pretty high replacement cost compared to a clear shield. I was going to buy a couple spares just for my commuting.
All in It's a good helmet. I gave it a 4 rateing because of the lack of a clear visor and the problems with the chin strap. It is a light, comfortable helmet, and with that Transitions visor it's well worth the money.