Having spent some time as a technical writer many moons ago, I know all about the traps and pitfalls that come with by-the-hour writing. However, it's given me a pretty decent knack for spotting when a writer is padding it.
Personally, I've been working with the same two writers for years, because I know their performance. They're not cheap, but then again they're not all that expensive either. And if you hold what they produce next to the average Per-Word post/article/whatever, it's like War and Peace next to See Spot Run.
And yes... quite right... In a Per Hour writing market, quality and cost-accountability will naturally rise to the surface. Much as is the case in the SEO-World, the fly-by-nights will come and go, but the responsible operators will basically be around forever.