One must also keep in mind the manner in which any machine is assembled before it is sold. Big box stores, if they did not assign bike assembly to the most junior and lowest-paid employee, typically hired a crew that came in periodically and slapped together all the bikes in stock so they could be sold (Assembly $10 extra!) if the customer chose not to take the product home in a box and do it himself. This was piecework and the quality of assembly reflected this, depending on the contractor in question.

Most bike shops, on the other hand (and I may be giving undue credit to "most" shops based on the engineer-owned one I learned at), took at least a little care in the assembly and setup, and pride in the quality and consistency of the work. The same Brand X bike sold by the big box store would be much more likely to have been shoddily assembled and adjusted than the very same bike built by almost any "real" bike shop.