So I have been flashing ROMs for a while now. I recently installed Jelly Bean 4.1. I used the OTA(Over The Air) version from here. Just make sure you also flash the Simple-Root.zip file. I did not. So I had to root my phone again and then install it. Which wasn't too bad but still annoying.
As with flashing any kind of ROM there is always the thought and reality that you could break something. I had a custom ROM on before I switched to a Jelly Bean based ROM. It had the nice notification power controls which was awesome. But Jelly Bean (or at least any of the ROMs so far) do not. So with a bit of searching I found Power Controls.
It works well and has a lot of customizable features. It is a recommend.