You will not question the weight once you start seeing the photos the 2.8 can produce. And it's really not ridiculously heavy.
Build quality - unreal. Mine was dropped (not by me, but I saw it happen) from waist-level onto a very hard floor. No damage whatsoever. That thing is a tank.
I would have cried like a little girl
The world did seem to stop when it happened. I had the lens in my camera bag, which was opened and sitting 'safely' on a table. I was demoing my camera to some high school students, and a student, trying to be helpful, picked up my bag and was going to bring it to me for some unknown reason. When the lens fell... the thud it made was unreal. Everyone kind of froze, and I didn't know how to react. But I tried to not make him feel too awful. Maybe just a little though.
I tested the lens exhaustively as soon as I was alone, sure something was going to be wrong. I couldn't find anything. It landed on the edge of the front element, in a way that the lens hood, on in reverse for storage, didn't seem to cushion the blow. Probably way more information than any wanted to know, but oh well.