In 1994 I bought a 1990 F250 with 7.3 IDI and Banks turbo. By the time I got the former owners errors corrected I had rebuilt the engine. While I was at it I did a bowl clean up on the heads straight piped it and tweeked the pump a little. Ran pretty good, made a lot of trips to the mounains with the horse trailer. In 2002 we had decided we needed a crew cab so I bought a 96 CCSB PSD. The wife (former truck driver) drives them more than me since I have a company PU. She gets in the new PSD takes off and says "so whats the big deal with the powerstroke? My old truck ran better! "
Of course now there is no comparison, but initially the turbo IDI ran better than the OBS PSD.
The IDI is more limited by design as to max power. But it can run pretty good and there has been a lot more development since 2002! The place to go is oilburners.net There are folks there that are very serious and have developed pumps, injectors, done intercoolers and more. If you accept the limitations and remember there is no computer to save you, you control it, 250 reliable HP is doable.