This could be an endless debate,the fact that there are many good/great engine builders out there the facts remain the same for everyone of them.Sometimes shizt happens thats is beyond their control ie: bad parts,other times it maybe an employee mistake,or a bad combination of mismatched parts.
As mentioned time and again paying for a good job is what everyone expects and thats normal business,screw up and the world will know unless the shop has the integrity to man up to any issue and work through the problems with each customer.How problems are handled is what make any good shop or builders reputation.Even if the problem was not the fault of the shop,they at least should help the customer fully understand what happened.
Also like in any business,sometimes growing bigger is not always better.The owners' name is on everything that leaves the shop,good or bad.In all my years of business if a customer has a problem then I have a problem.Many shops hide behind the fact that they build race/performance engines or componants and after the money changes hands they are resolved of any resonsibility and this leaves the customer no recourse but to complain and the internet gives them a world wide audiuance.
The only thing I can recommend is find a shop or builder that you trust,have confidence in and can build a relationship with them so that any issues can be worked out together.