I live in Grants Pass and take 199 to the coast three or four times a year. I'm driving a 40' Allergo Bus and pulling a toad so my opinion has some relevancy. Most of the road is two lane with a few short sections of four lane and there are some passing lanes and turn-outs. The twisty sections are narrow and need to be taken slowly. When the road sign says 20MPH it means you! Just past Hiouchi there is a right turn onto 197 that saves about ten miles if you are heading north. Again take it slowly and you'll be fine.
The Oregon coast between Brookings and Gold Beach is some of the most beautiful in the world, I never get tired of seeing it. If you can hit it at low tide you can walk out past huge mountainous rocks and enjoy exploring the tide pools. Bob