Hopefully, this may be of use to others.
I have been underwhelmed by the power of my Qashqai (when compared to my previous car) since I've owned it.
Even though the power/torque specs were similar on paper it just didn't feel as lively.
I'm pleased to say this is now resolved and it was very easy - I just replaced the air filter (16546-4BA1A £21 ouch).
I understand that item is normally replaced every two years but mine was almost totally blocked at approx. 7k miles and a little over 1 year old.
I have attached a picture but this shows the old air filter already having been partially cleaned - it was way worse than the picture shows.
I don't know the history of the car prior to my ownership so I don't know how the air filter go so dirty.
Much happier with my Qashqai now