I work online Mixing and Mastering and have been for around 8 years. I find it is easy to work this way as long as you get on with the clients.
I have had hardly any problems Mixing and Msatering online with clients.
Here is some of the comments people have kindly left me on my page. And also some samples of work I have done.
Crystal Mixing (and Mastering) on MySpace Music - Free Streaming MP3s, Pictures & Music Videos
PM me if you are looking for any Mixing or Mastering.
Cheers,
Eck (G)