As John said it's all about the "look". One piece or two piece depends entirely on the look you want and what you are happy with.
For years we have been having the glass shops butt the glass together for the "one piece" look and the results weren't always the best.
Due to the fact that I have to have tempered glass made for my doors I intend to go through Bobs. It's about a 4 hr drive down there and have them do all of my glass for the 48 the next go.
Note: On the tempered glass on the doors. No frame due to the chop and laminated hasn't held up.
