J - By definition they wouldnt be the same kind of spec! One has increased the power the car is producing by adding NOS. And I think I'm right in saying its not something you can just bolt on and go. It takes tuning and tweaking like any other mod.
There is no art in me paying some mechanic �2000 to fit new cams and piggyback ECU. But it gets me some extra power and it's just me shelling out some cash.
Tommy K has done one of the best things you can to a JTD by unleashing its extra potential. And as he says, it's just some clever re-programming. I would never write an enhancement like that off because it's too easy.
As it happens I fitted and tuned my nitrous kit myself so I happen to think it is an 'art' producing the most power it can without blowing my engine to bits.
I think the reason it's always written off is it gives great power gains for initially a low cost so people think there has been no blood sweat and tears involved. But in reality, it's an expensive way to add a lot of power as you have high running costs. Each to their own though and I wouldn't personally change it.
Dan