I feel your pane
(sorry, couldn't resist)
I just had mine done. The shop said they could put in glass from the same vendor, but without the star symbol, or MB glass (The crack was in an area where forward vision would be distorted, so it couldn't be injected for a cheap repair.) There is an older thread about the relative hardness of factory vs aftermarket glass in the archives. I wasn't that worried about the surface durability at this point.
My insurance was covering it, with a $250 deductable for either MB or aftermarket glass, so I opted for the MB factory glass. I didn't know if it would have the Mercedes Benz Product white signature decal on the new glass, so I picked a decal up from the dealer while waiting for the glass. When it arrived, the tech pulled the old windshield, laid a couple of shop towels on the inside surface, put the new window on top of the old one, and alligned the decal with the old one. Perfect placement match.
I wasn't just being anal about the decal and star symbol. A friend who worked for the MB dealer told me if they see non factory glass and missing decals at trade in time, they start thinking "collision damage" and even if they can't find any traces of repair, try and deduct something from the trade in.
Funny thing is, the dealership gave me the wrong decal! I asked for the MB product signature decal for a 1998 - they gave me a Daimler-Benz signature decal like my 87 300E. I didn't notice it until I was cleaning the window several days later.