We just had a big thread about a guy who had excess
oil consumption, and the way that Roush handled that was exemplary. I think Keith Craft, Roush, Performance Engineering (just to use some examples) all do a fine job regarding building a motor, and servicing the customer. That extra money for Roush funds a bigger operation with more resources, they do a little more R&D and vendors like MSD have special part numbers for Roush motors, which makes the Roush motors more like production than custom. The smaller shops like KC and PE give you a more personal touch, it's nice to talk to Keith with his 30 years of racing experience behind him. Your motor can be more unique, built to your exact specs. That can be good and bad depending....
I'm thinking that it might be less stressful in the event of a problem motor to deal with Roush, especially after some time has gone by. Of course Roush also has some fine print in their contracts which has caused comment on these forums.