No real difference in performance from OBD. The acronym stands for on-board-diagnostics. They are just two generations of the same thing. Most people go with obd1 electronics when upgrading/swapping their motors because people like hondata/uberdata have come up with economic solutions on how to tune the fuel and ignition maps for maximzing a motor's potential performance, without having to go out and buy a stand alone system, such as a MoteC or Electromotive System. If you have a LOT of cash to burn, go with one of the last couple of names I just mentioned. They are at the top of the EFI fuel chain, and were built from scratch as a fully programable system. But hondata/uberdata is more than enough for 98% of people out there, and hondata and uberdata don't work with obd2 i don't think. I guess the programming language for OBD2 hasn't been worked on yet or something. The only people I have heard of doing performance on obd2 honda ecu's are the big guys like mugen and spoon.