Enterprise was great, but could've been better.
The Xindi arc , Temporal Cold War, and Borg appearence were big let downs for me. The conflict between the Vulcans and Andorians was a great story arc as were the episodes concerning the transgenic Humans. The Enterprise could've been more inline with historical design as well. I was hoping for something along the lines of the Comet Class.
BTW, I loved the theme as well. It captured the mood of the series perfectly, IMO.