As stated many times, "it just depends". You just can not expect to have your knife worked on right away when dealing with a very small shop. You most always get your repair work back soon when dealing with a company as large as Benchmade and Spyderco. Those companies have employees doing only warranty repairs. Small companies like Brous, Strider, CRK and such do most repairs when they slow down a bit, or do a few in between. I have no issue waiting for my knife to come back because I know it will be right when I receive it. You will hear people say they waited 6-8 months to get their knife back, and it was the same as when they sent it in. Well, they are generally so made by the time it does arrive that no matter how good it is they will find fault.
Then there's the quality of the product. You can not compare Benchmade or Spyderco to the quality of a Brous, Strider or CRK. Jason, Mick and Chris's work is far beyond any Benchmade or Spyderco, and quality takes time. Every company makes mistakes no matter how good they are. Oh, and if you do constantly send emails, and call, they will keep putting your a few spots back every time.
These are my thoughts, and mine alone YMMV.