I love this helmet. I'd definitely buy one again and would obviously recommend it to others. My only real complaint against it is the large gap between the visor and the supposedly "perfect fit" goggles designed for it. If the two vent wholes on the visor itself (for the goggles) had an open/close mode, I think that would help a little towards a warmer face, but honestly, the cold days require extra gear all-round to stay warm and the face is no exception regardless of the helmet.
The entirely helmet is warm in cold weather and a great wear. The ear flaps are specially warm and they don't miss a spot. There is sufficient mesh and venting internally to keep your head from sweating while still allowing the opening/closing of the external vents when needed. The only area of coolness - which isn't entirely the helmets fault so much as a product of circumstance - is the gap between the visor and the "associated" goggles (Prophecy Turbo) affecting you on cold days. The gap is large enough for quite a bit of air movement along the forehead, but also easily solvable with an under-helmet balaclava for the colder days. Although the helmet itself is warm enough even for the coldest days, the forehead is an important place to protect.
The sheer look of this thing is like something out of batman. It's amazing to look at, especially with the moving vent covers and all. I felt like a kid on christmas playing with the vents for the first 5 minutes.
Given the great fit, warmth and comfort level on this helmet, I'd definitely say it's great value for money. You have the option of using it on the coldest and the warmest days with the moveable vents and cost reflects that advantage.
I'm size M and the fit is great for me. No complaints here.
Solid build. This thing isn't falling apart anytime soon, let me tell you. The quality of it is quite brilliant and expected of the cost.