Yeah, I have experience with venlafaxine er (Effexor XR). I currently take 450mg of it, but I understand the doc's concern about it causing mania. I've never been manic (though I have schizoaffective disorder, so I suppose I could get manic at some point (let's hope not)).
Anyway, Effexor, at the right dose, gave me a huge boost. I know I can attribute some of getting out of my worst depressive episodes to Effexor. Seriously, it's a good med if you can tolerate it well.
What helped me with being successful with Effexor was getting a blood level of it. I learned that I am a fast metabolizer of Effexor, which means I have to take relatively more of it compared to people who metabolize it regularly. Armed with that knowledge, my pdoc and I were able to raise it to a level that was and still is good for me.
Hope that helps. Also sometimes they pair it with Remeron. I currently take both Remeron and Effexor for my depression and that combination lifted me out of one of the worst episodes I've ever had.
Just some ideas.