I got a Merlin 3 and it seems like a good block to me. Much nicer than the factory block I had before...can't say about the Dart but a friend of mine had a very rough time with customer service there as well..he bought a new aluminum small block and it wasn't right and had to be sent back...says he will never deal with them again. I think no mater who you deal with in whatever business there are going to be some problems every now and then...that's just how it is...nobody's perfect.It is how you handle those problems that determines your "worth" for lack of a beter word. I am not bashing Dart at all just pointing out that mistakes happen to all of us.
JMO