Well, you shoot a scout-scope-equipped rifle with both eyes open, just like iron sights. The scope therefore blocks nothing (unlike an ordinary scope which is much closer to the eyes).
I just went down and did an informal test of sighting. My Leupold scout-equipped rifle was perhaps slightly behind my ghost-ring-equipped Model 94, although that is arguable because the scout also gives the advantage of a single focus plane and 2.5 power. The scout was easier to sight with than an AR-15 (with all it's protective wings, front and rear), and way easier than a 6x conventional scope.
By "handy" I mean it doesn't add much weight (compared to conventional scopes), but more importantly I can grasp the gun around the middle which I like to do - heck, I'll carry the gun all day that way. And it won't have a front sight snagging on things. I'd put it perhaps just behind irons in handiness, and way in front of a conventional scope.
It has a narrower cone of view than a conventional scope, but that doesn't matter with a stocked gun because you put your face in the same spot on the stock every time anyway. It's not like sighting with a scoped handgun which I admit is difficult.
A scout scope combines the handiness of irons with the single focus plane of a conventional scope, and modest magnification. A compromise, but a good one. Another way to look at it, it's iron sights for guys too old and blind to use irons any more.
Harder to fog the lens with your breath, and no scope cuts for hard kickers either. :-)