The DIG-S is a really fun car. I love mine (well, correction, the wife's but 'borrow' it where I can). No, its not the fastest car on the road, but surprises a few people. Certainty makes my 1.2 DIG-T Qashqai feel like a lump of lard!
You are right that the boost is limited to around 5/6psi according to one member, but as you say probably wont be difficult to find a bit more hp out of the engine but I dare say it would need a good map to tweak a few things.
