I have been on the Nuvaring for almost 6 mos. now and I love it! The first couple of months, I had a lot of nausea and headaches, but that is mostly gone now.
I haven't really gained weight, except maybe a little in my boobs (lol!), and I haven't noticed significant mood changes. (Also, I am prone to anxiety and depression and still haven't had a hard time).
I recently switched to a 28 days in, 7 days out schedule, and I'm currently having a relatively heavy period, though it's only been 21 days. But, it takes time to adjust.
My husband loves it! No sensation problems, but, after 8 years of condoms, this is a HUGE improvement!!
Best of luck!