Welcome!
If your going to swap it to a HDI you may as well buy a normal 306 HDI as it would be cheaper to buy that than change the engine if you sold the NAD and would be much less hassle
I love my HDI to be honest, not so much when it was standard but when you start tuning it is does go well and can keep up and surprise much newer and more expensive cars
Each to their own though so good luck with whatever you choose
If your going to swap it to a HDI you may as well buy a normal 306 HDI as it would be cheaper to buy that than change the engine if you sold the NAD and would be much less hassle

I love my HDI to be honest, not so much when it was standard but when you start tuning it is does go well and can keep up and surprise much newer and more expensive cars
Each to their own though so good luck with whatever you choose
