Salomon recognizes that there are a lot of runners who are running on mixed terrain- a combination of roads and trails, and have introduced their City Trail line of shoes, with the tagline "The cushioning and ride of road shoes with all surface grip and protection for varying your workout."
The Salomon X Scream is one of the shoes in that line up. I've put in about 5 or 6 decent runs in these shoes to get a good feel for them before writing this review, and I have to say, I'm pretty impressed.
First of all- the specs. These shoes (for a men's 8.5) weigh in at 10.3 ozs- not super lightweight, but not clunky either. The heel to toe drop is 9mm (19mm at the heel, 10mm at the toe) which is more than I typically run in (the majority of my running is in Altra shoes, which have 0 drop), but felt surprisingly natural for my stride. The overall feel of the shoes is that it's quite firm underfoot, which works well for smoothness on the road. The toebox is a bit narrow for my foot, but that's more related to my freakishly wide forefoot than the shape of the shoe.
Now to the performance...........
On the road, these shoes feel like road shoes. I would have no issue wearing these for a long training run on pavement. They feel smooth- exactly how you'd expect a road trainer to feel.
On the trail, these are pretty good too. Keeping in mind that these are meant to be more of a hybrid road/ trail shoe, you can't expect them to perform exactly like a full on trail shoe would (Salomon has plenty of other shoes in their line up for that). On smoother sections of trail these felt great- the grip was good, and they feel fast. There isn't a super aggressive tread, but it was surprisingly sticky on sections where I thought I might slide a bit.
In summary, these are excellent shoes for someone who runs on a variety of surfaces. If you only want to buy a single pair of shoes that will perform well on the road and on gentle to moderately rough trails these would be a good choice. If you're in a situation like me where you run on the roads to get to the trails, these are a good way to get the best of both worlds in a single pair of shoes.