I bought the D-Max Utah last July and have clocked up 10,000 trouble free miles, economy is good on standard tyres but having changed them to GG AT's it is OK on runs 35 ish, but short journeys knock it down to 27. Mines an automatic with Truckman canopy.
I have had it remapped so more torque and bhp, but this did not make any difference to the mpg, its definitely the tyres that did that!
A mate has the Ranger and having driven mine he wishes he bought the Isuzu.
Also, shop around I ended up paying £21.5k + VAT for a fully loaded one with SatNav and reversing camera.
HTH
Nick