The guy who owned my condo before me left a snow shovel and broom in the utility closet. Yesterday after receiving a foot of snow outside DC I used them for the first time outside. The shovel must've weighed 20 lbs before it even had snow on it. Now I know why he didn't take it with him.
Got any recommendations for a particular material or shape you've had success with?
I'd say you're doing it wrong - you shovel every three inches or so at the latest.
That said, I have two snow shovels. One is a big wide pusher. It's about as wide as a push broom, heavy plastic with metal edge. Like you said about yours, it's heavy on its own, but I use it for most of my shoveling.
I also have a cheap one I bought at the grocery store - wood handle, plastic blade and plastic grip at the end of the handle. I use it on sidewalks or if the snow is too deep for the other one.
I have to admit I feel pretty bad-ass shoveling when all the other neighbors are using their snowblowers. I was a little jealous of them once this year when there was a LOT of snow to be moved.