Having loved the original Sparks, I picked up a pair of these (although for far less). Overall they're a great shoe, but there are a few things to consider. First, due to the GTX insert, these will not stretch out a little bit like the normal Sparks. Even from the get-go, they feel narrower than the Sparks, so if you have wide feet, you better try on a pair. Second, I stress fractured the top of my foot a couple of years ago and these shoes (due to the tight fit) occasionally put somewhat uncomfortable pressure on that particular spot--usually only during walking, not running. Anyhow, that's not really the fault of the shoe, but an issue I have. Third, as others have mentioned, the grip is good on these shoes, but the rubber wears out pretty quickly, especially if you use them on the road at all. Scarpa should use a different rubber compound, however it might cost them some weight savings. Last, for going down trails fast, I feel the narrow fit doesn't provide as much control as my Altra Lone Peaks.
On the plus side, these shoes keep you dry, they're light, and they have minimal drop. I use them on the road, on the trail, and everywhere else. I like their styling and they don't unnecessarily stand out like some other trail running shoes which means I can wear them with jeans or whatever and not look like a complete dork.
If they had a more durable outsole, I'd give them 5-stars.