Autogenerated code is clothes off the rack. Hand generated code is custom-made clothing. Unless your body is off the rack, off-the-rack clothes won't fit as well as custom-made clothing. They probably won't look as good or last as long either.

I prefer to generate all my own code - that way I understand all of it, not just most of it. (Now if only I could remember to make my documentation adequate enough so that I could still understand all of the code 5 years after I wrote it ...)