I always read in the s13 community to avoid Nistune in favor of Ecu Master or Haltech or something like that. Just this morning a friend told me about Realdash support for Ecu Master.
edit: I just asked him again why to avoid Nistune,he said because it's relatively expensive and has less functions than a stand alone ecu.
He may be biased because he just bought an ECU Mastere ecu for his JZ swap