I recently had a play with MediaPortal 2, having not played with it for years. It is really stable and works really well. There are still some areas that need to be worked on, but I personally believe that it is ready for use as it is.
If you are planning on using it for watching live TV from a tuner card, then the setup instructions are identical for both MP1 and MP2 TV Server.
The client side for MP2 is much simpler than MP1 and will work out of the box. Just tell it where your various files are (music/video etc) using the remote control (there is no separate setup, it is all in the main TV interface via the remote) and you are off to the races.