all I can tell you is the tools they sell are cheap for a reason. Yes I have ordered from them before and the quality of the tools are at the least lacking. Thats what you get for cheap money but that just my opinion and experience.
Take care
I dunno, my tile saw cut through glass pretty easy.
I ordered my bits from some shady guy in Hong Kong on ebay. That being said, I but 2 holes though 1/2" glass, and 4 holes through 1/4" at this point, and hte bit seems to be holding up fine. I payed $8. I think he sells kits that have a bunch of bits for around $25. Let me know if you want his username.