Solar roof panels - anyone got em?

[Notshortnottall]

Long story short - bought a house which needs a lot of work doing and looked at having solar panels fitted on the roof.

A chap came out to give me low down on it all (feed in tariffs, different options to buy/rent etc) and walked through how much i could receive back by 'selling' excess energy back to the grid.

This all just seems too good to be true so would be interested in hearing how other people have gone about it and if it's been a worthwhile investment or a waste of space.