I would imagine the Fit and Finish, ergonomics, material choices and overall user enjoyment would be superior to the production version.
Customs obviously have a more personal touch to them. they are checked individually, and any problems that arise are generally dealt with prior to leaving the maker's hands. This isnt always the case with production companies. as good as their quality control can be, pushing out that many knives there are bound to be bad eggs.
Ergonomics would be superior because the company has to pinch pennies on the "bell and whistles" where as a custom is a full-on all out deal. of course that isnt to say productions arent as comfortable as customs but this is all under umbrella terms.
material choices, again with customs anything you want vs heres the model with a few sprint run variations. any other mods you can do yourself.
User enjoyment is more preference then anything but my thinking is that if you spend the money on a custom then it should be able to do whatever its job is better then a production model (IE If you want a slicer, it should have really thin stock, a beater knife proper blade geometry etc)
of course your mileage may vary
