I did loads of research before buying a tuning box for my focus tdci sport. I found that the Roverron tuning boxes which can be found here http://tuning-diesels.com/
were one of the best to buy. Its got ten setting and im currently running mine on nine. They make a huge difference to the power delivery and take 10 mins to fit. Ive also disconected my egr valve by removing the vacumn hose and sticking a bolt in. That mod has also made the power delivery smoother and would recommend it.