Opinions on Seiko's 4R and 6R movement quality from those more able to judge

[SidKop]

I read a lot about the quality (or lack thereof) of Seiko's 4R, 6R, 8L  movements...or more specifically the lack of regulation from the factory. Especially when compared to similar priced manufactures using SW200's or ETA's. I thought I'd ask those more in the know, do the 4R's and 6R's deserve their bad reputation, is it fairly easy for someone with minimal skills (or better yet a trained watch mechanic) to dial in these movements to a more acceptable performance. 

 

For background I spent more on a 1861 Speedy years ago, expecting that the advertised 0-15s/d  would probably perform more like 5-7s/d. In reality it's been closed to 2-4s/d.