r advantages
No-one can trace you to external IPs visited
Distributed network – almost impossible to shut down or attack in a meaningful way
Free
Tor disadvantages
Very slow – because your data is randomly bounced through a number of nodes, each of which could be anywhere in the world, using Tor can be painfully slow
Not suitable for P2P filesharing – while there is no way to stop you from using BitTorrent over Tor (and people do it) it is a) very slow, and b) very bad form as it slows down the entire network for every other user, for some of whom access to the internet via Tor may be of critical and possibly life threatening importance
While it can, at a pinch, be used for location spoofing (see above), Tor is a very fiddly and inefficient way to go about it. In addition to this, the slowness of Tor means that using the service to stream geo-restricted media services is unfeasible.