Well, if you haven't gotten the Prometheus Lens. You're missing out. It shipped with a bug and is way overpowered. Bungie admitted it and will fix it in tomorrow's 12/12 update.
Right now, Xur is selling it. I have played Friday, Saturday and Sunday in the Crucible and it's the new meta this week and I'm having a blast.
I went in to the Crucible just to play around and have spent hours just blasting and getting blasted by it. I had 19 kills in one game with it. That's my best so far.
If you haven't had a chance and are going to be on tonight, pick it up and go have some laser tag fun... It will all go away tomorrow after the update.