ktuner allows for a lot of changes to the driving dynamics of the car such as faster turbo spool, less throttle delay, dynamic VSC, and much more. When I got the car, stock from a 40 roll it got gapped by a stage 1 civic si. So its not as fast as people say. Its quick once youre in boost, but it has a pretty crappy top end (past 4500 RPM) and the turbo lag is absolutely ridiculous compared to the 1.5, Id say from a dig the turbo will be in boost only by 3500 RPM even though honda advertises "peak torque" at 1500 (I call BS, there is literally no way that can happen considering the transmission keeps the car at 1400RPM MINIMUM at any speed). On 93 octane and stage 2 youre gaining about 88lbft and 60whp and torque comes in earlier and doesn't fall off as hard. I still average well over the rated MPG on the highway, so the trade off is none...smoother and better power at more RPM, the only risk I can think of is faster heat soak of the intercooler and more turbo wear if you run the car hard all the time.
The k20 as an engine is nearly bullet proof as long as its well taken care of. My issue is literally NO ONE can seem to answer my question of long term 5w30 usage on this engine specifically.
EDIT: if you have little experience with turbo engines, the realization hits hard that its just a 2.0 NA engine with a big spinny boy strapped to it to "make the rated power" when in boost, when not in boost, its just a 150hp civic motor in a giant 4 door sedan, trying to make a gap split second in traffic or merge in high way traffic its harder when you need to get into boost to do anything, hence why the early spool is by far the best feature of the tune.
Factory its 252hp 273lbft. With stage 2 (and by the way, you need zero mods to do this) you're making well over 300lbft at earlier RPM than stock and peak at about 330.
EDIT2:
For reference, the only difference between the civic type r and the accord 2.0 are more aggressive cams and bigger turbo and intercooler. The engine was designed with 500hp+ in mind, you're limited by boost obviously.