Well, first of all, the standard disclaimer -- not all meds work the same for all people.
I have been on Effexor XR for about 6 years. The only side effect I had was right in the beginning -- I bounced off the ceiling for about 3 weeks, until I started taking it in the morning instead of at bedtime. Once I figured out that it was going to wire me instead of make me sleep, and adjusted accordingly, everything since has been fine.
Your mileage may vary.
Candy