I have a seedbox at Seedstuff.ca It costs me $20 a month, for 225 gigs of space. The setup was less complicated than I was expecting. The interface (ruTorrent) mimics my uTorrent, and once I understood this, I had no problem using it immediately.
I think it has many great advantages. I can leave my files there, seeding for a very long time, even if my computer is turned off (which it was this week when I went out of town). My ratios have gone up exponentially. The seedbox has much greater bandwidth than my own ISP, so it is blazing fast. My own IP address isn't ever seen in the mix of downloading and uploading peers, only that of the seedbox itself, so the security is very good. The seedbox software does occasionally crash, and there is a manual "reboot" link from a different website, a godsend when you can't log on. Overall, I'm very pleased with it.