well i have never had one, but i have a 2.5 td, and a 2.5 diesel N/A vehicles. both straight 6
slightest hill and the N/A comes to a crawl, its a nightmare on long hills (not even that steep really) and its a case of changing down to first often and going up at 10/15mph...or 2nd and it revs high, but third is too far away.
now in the turbo one, its just as slow until it hits 2200 rpm, then the surge really kicks in, and rockets away. and car will be sluggish as hell, unless you use the gears right. my tds is a auto, and while i dont mind autos on powerful cars, the kickdown isnt too great on the tds (its great on the petrol version had them before). i can be going up a hill, say in rush hour so its crawling along, but then when the cars are speeding back up, mine is sooooooooooooo slow at increasing speed and rpm, if it was a manual i had have changed down, built the revs up, but even with auto kickdown, its not quite good enough. its fine at a 140 all the way up in S mode. just not so good at going slow.
my N/A camper is fine, just not on hills.......rest is fine.
one has under 80bhp, the tds 150. a turbo unit makes one hell of a difference, but its knowing how to use it too. cant say fuel difference would be great, unless stopping n hill climbing a lot. both have lots of torque which is what you need, not bhp.