IIRC, I think that in my few hundreds games of online Dominion, I've played Scout exactly once (and even that was BoM as Scout). Like everything else in Dominion, I guess Scout has its uses, but in this particular case - it's so niche that you'd have to design a board for it.
With that said, I think Scoiut should be evaluated while keeping in mind and expansion it was a part of - Intrigue; which can also be played as a standalone game. And in such surroundings, Scout is better than usual (which is admittedly, not saying a lot), as it has much better chances of being part of the same board as Nobles, Great Hall, Harem, Wishing Well...