i have the smith hustle and my friend has the smith holt. I feel they are relativly the same in shape and size except the hustle has an open and close system on the vents on the top of the helmet.
I've rocked both oakley ambush and electric eg1s under the helmet and they fit fine.
To the durability note, this was my first year skiing and i was skiing glades (trees) with a friend. Long story short I bonked my head on a tree at a decent speed with my helmet, aside from the knockback and embaressment i was fine.
smith maze. best helmet out there