Played some this morning. To acquire the new weapons, you need to complete "assignments", so I haven't used any yet. There's like seven flags in conquest on Gulf of Oman. I only got to play about fifteen-twenty minutes and the game crashed on me. I got a silver star for my SIG, too and the thermal scope for it, so that kinda rubbed me the wrong way. Don't feel like getting in and trying again, because game crashes just really turn me away from games. Hopefully, they fix it real soon, otherwise, look forward to a new list of issues, folks. Not saying it's imminent, but very likely.
And don't bother looking to the community for help. The BF3 forums might as well be CoD people. Full of a-holes who completely corner you the minute you criticize their game from Heaven.
EDIT: Apparently, even if the game crashes on you, when the round ends, you get all your stats you earned for that match back. I see my silver star for my SIG and the thermal now, so I'm good.