I've been on Rebif (Interferon beta 1a) for almost 2 years now. I switched in March of 2010 and it's working well for me. My neuro at the time did not want to bring out the "big guns" as in Tysabri or chemo therapy and wanted to see how an interferon would do. He did, however, also see if I was interested in participating in a study with Gilenya, which I did not do. I had an MRI done in March of this year to see where I was and if the Rebif was being efficacious. There was no new activity and I decided if it ain't broke, don't fix it.
I know how overwhelming it can be to read through all the literature, watch all the DVD's, etc. when you're researching therapies. I thought my head was going to explode from information overload! Part of my Rebif decision was ease of injection. Like the Copaxone, pre-filled syringes were a positive. I've also heard good things about the Gilenya, and it's oral.
Good luck with your decision. Hang in there!