Can's speak tot he Hammond issue but, with respect tot he drilling issue, I've heard anecdotal reports from people who had both drilling and printing done on the same enclosure that the drilling was off by a millimeter or so. However, these reports seem to be fairly few and far between so I expect most of their drilling jobs don't go out of spec but Tayda emphasizes the 1mm tolerance so that they don't get complaints when they do drill a bit less-than-precisely.