I can't tell you how a Clockwork Creature mask measures up to other fursuits because I've only ever tried fursuiting in CC costumes, but my personal experience is very positive! The masks are extremely light-weight, though possibly a balaclava/foam-based mask would be even lighter. I weighed Ngala once and I believe her head is about 800g in total, horns and all. The horns are extremely light, although I think Qarrezel has begun making them slightly heavier for increased durability. It's definitely no strain on your neck, though!

Ventilation is good as well. What I like about Q's masks is that they're constructed from shaped resin; the forehead-pad and the chin-rest for moving the mouth are the only points of contact between the mask and your face, meaning air can circulate inside the mask and it won't soak up sweat from your skin. It can get /very/ hot in a fursuit, especially in a full-suit, but unless you install a fan in your mask I don't think you'll get better ventilation than in a resin-based mask.

As for vision, it's somewhat restricted, though I'm sure it could be worse. The mask's eye-size and muzzle-length influence your range of vision somewhat; generally, Q's masks range in vision from bird > feline > canine, with birds having the biggest eyes and therefore also the biggest tear ducts and best field of vision. I don't know about dragons/dinosaurs. In my case, Breynz actually has much better vision (and ventilation!) than Ngala because the mask is so open, with no faux fur covering the muzzle, giving me almost total vision. In Ngala I can see perfectly ahead of me, but have no peripheral vision. I prefer having a handler with me as Ngala to keep me from tripping over things and/or being surprised by people approaching from the side, but as Breynz I can manage on my own and have done so in the past. :)

I hope that answered your questions?