Nathan,
I am currently taking effexor. It has worked well for me. Yes I did gain some weight initially - I wasn't aware nor warned of that as a side efect. I have been able to lose the weight I gained so if you are careful you can probably manage. My biggest complaint is the withdrawls if you miss a dose. I get a headache, light headed, and overall my head is real fuzzy and crappy for lack of a better description.
Ativan knocked me right out to sleep but I woke up with a headache. Also, I like to get up reall early and work out in the AM (5-7AM). Very difficult to do when taking ativan. You will sleep a full 8+ hours. I don't have much trouble sleeping anymore so I haven't taken it in about a year plus.