I've played a couple of matches just to see what it's like, and perhaps I'll play more when this singleplayer backlog is cleared a little bit.
It didn't really strike me as anything extraordinary. It's mostly just cover-shoot-run like Uncharted and most other multiplayer TPS, without the platforming dimension. I do like the crafting, and I think that's where it starts to shine above other multiplayer shooters. I hope they put some more emphasis on that in future; there's no reason why they should be limited by Joel's crafting capabilities in the single-player. For now, it's a solid multiplayer segment, and I'm glad they included it (since the single-player was already so excellent).