I was using it for some time until they started to use all kind of tricks to force me to upgrade to the more expensive plans. It started from $5, then I was paying $10 and after the next "upgrade or we remove your account", I cancelled.
I have had contact with the support of put.io more than once, and they were always very friendly and helpful. (even if some of the request were things such as "add play.fm support").
The big advantage over anything else I've seen with putio is that populair torrents are downloaded in a matter of seconds (due to someone else already having downloaded it) and the mp4-conversion. Btw, a small tip, instead of using the site itself for watching media which is downloaded, you can stream it directly into VLC or MPlayerX (the later also support streaming youtube video's I believe) which is very very handy!
Just noticed, there is an option for the legacy 10G $5/month account: http://lry.be/WRxO