I've been on it for 2 years (recently just stopped it to give the MAOI Parnate a go). For me (and coincidentally, my flatmate who takes it as well), it helps a lot with depression. I found it helped more with depression than it did for my particular type of anxiety (social fears, can't-look-people-in-the-eyes disorder, self-doubt, fear, fear, fear). This may or may not be the same for you, and I guess depends on the intricacies of your particular issues.
If Parnate does not work for me, then I will either go back on Pristiq or try Parnate's sister drug: Nardil (edging more towards Pristiq because of low side effects). Pristiq could end up working well for me again, but I'd need something to assist with my social anxiety as well, be it a benzo or marijuana or psychedelics. To note also, I didn't have huge sexual side effects when on Pristiq (I've tried a lot of antidepressants, and Pristiq was the least detrimental to my sex drive). But on stopping Pristiq, I have noticed the return of a higher sex drive.
I could also never sleep properly on Pristiq as it was probably too stimulating for me, but apparently stimulation drugs un-stimulate a lot of anxiety sufferers, so it just depends.
My advice to you is to jsut give it a go and if it doesn't work after say 6 months as max dose (100mg), then you'll know it's not for you. I've been off it for 2 weeks. The first few days of withdrawal were a bit uncomfortable and I stayed in bed with a headache and lot of annoying brain zaps, but they're all gone now and I'm clean and ready to move forward.
Good luck