Originally Posted by
7ypeR
When running an ecu in the s2k, you can't piggyback them so you will have to run a stand-alone. This includes the hondata, which requires you to buy a the full kpro ecu rather than plug into your factory unit. In saying that though, the price is quite exxy so you might also want to consider the Autronic or Motec units. Only thing obviously being that Hondata is a factory honda unit so it will probably RUN your car the best. Whether or not it tunes better, you have to contact your tuner.
On another note, I can understand what your saying about weighing up cost v benefit. You may get only give/take 3-5kw on top of the Apex Neo but that does not include the gains from low-mid range tuning. With the complete ecu, you have a tuning window for low cam (non-vtec), and a separate tuning window for high cam (vtec). This means you could probably adjust the tuning points for every 100-250rpm compared to the Neo which MAY be every 500-1000rpm (guessing).