I had minimal benefit the first time I was on Effexor, about 10 years ago, and I can definitely vouch for the horrendous "discontinuation syndrome."
I came back to it, though, after having been on everything else, because it came up as a good match on genetic testing.
This time I'm on it in conjunction with Abilify, and I'm really experiencing some relief, notably from anxiety, but a fair amount of relief from depression as well.
Drug combinations make a difference, as do genetics, it would seem.