A Scout built out of a city with Barracks and Armory can have 4-tile sight range right off. This lets you stand off on a hill and spot for Artillery and/or Bombers without fear of attack from Artillery stationed in the city. I picked up a tip from this forum to remember to build a few scouts before Scientific Theory and if you're warmongering you should have a city that can produce one scout per turn at this point in the game. It's a useful unit to have, besides just spotting for artillery it gives you a slight tactical advantage, especially in hilly/forested terrain.
I'd still be wary of melee counter attacks to take out my spotters.
Yes, it is true that by the time Dynamite rolls around, one should have at least one city that can pump Scouts every turn. Heck, that's why I like Military Caste so much as a warmonger...if the majority of my cities are connected by road to the capital, then I can quickly increase happiness by 1 AND culture by 2 every turn...that is, assuming my cities weren't already garrisoned to begin with.
:: shrugs ::
I guess I just don't like the tightrope act that I'm forced into any time I use post Classical era Scouts in any meaningful tactical or spotting role. Sure, it's fun to batter down a city's defenses to zero in the Industrial era, and send the Scout in to actually take the city, but I wouldn't consider that to be a useful tactical role.