It has a lot to do with A) how much will you lose on your car if you sell it B) The car you've got is a good example...why sell it to buy a questionable GT-t C) are you crazy enough to do it and D) do you like seeing people question the lack of factory gauges and say "but I can hear a turbo"
Seriously though...if you check the specs on the RB25DE Neo compared to the RB25DET Neo...you won't find much that the 2 don't share, even cams are almost the same unit 2ms exhaust duration seperate them both!
The R33 RB25DE and RB25DET are a whole new ballgame...different parts completely.
I found the whole process to be worth it in my eyes Luckily I've done all the hard work...and found out the hard way what needs to be done...so I can make it a fairly easy process if you decide to do it.
Dan