I actually take the time to read those hubs and comments, to see what I can learn from people who are successful here. Usually the hubs speak for themselves and I'll comment myself and follow the person. There are many better writers than me out there, and I'm always very flattered when any one of them leaves a comment on one of my hubs. It's great to meet with great writers and read their work, it can only improve mine and contribute to my own success which surely only comes as the result of a lot of hard work.
So my answer is no, I don't suffer with envy. I use it as an inspiration!