sounds like you have had some pretty good luck with glass holes and their customer service. Im glad to hear this because i just ordered two diamond hole saw bits from them, sorry to hear about your 'chips' but it looks like you have found a solution. Good luck!
if I may ask the questions, what kind of drill do you use? and what amount of pressure do you apply to the glass? I have tried to drill holes on bottles and it chips out with out failure, but this is for practice for my tank that I want to build.
i just read this thread from page 1 to finish, and all i can say is wow. i intend to do a diy 300 as soon as i get back to the states and you have truly inspired! alot of the things you covered have been what i've been researching non stop and you definitely offered some clarity on some points. keep up the greatness man and congrats on the son.
Thanks again. I just used a regular hand drill, with light pressure on the glass, low RPM, and went slow. Keep the area wet so the glass doesn't overheat. It isn't very hard with a little practice.