I just ordered mine from envelopme, so I can't share how that went yet. But, I did order the sample set from the envelopments site and it all seems very good quality. I definitely recommend doing that, since the color I was going to purchase was very different in person and the metallics were much more shimmery than I expected!
I just bought mine from http://cardsandpockets.com/
I'm really happy with the service I've had and the quality of their products. I haven't started my invites yet though...