What are the odds that people who are looking to race their cars haven't modded?
I'm not surprised that a new N/A 3.5 v6 is close in performance to a F/I 2.5 h4.
Look at the upgrade paths for both engines. Assuming you are looking for reliability and a reasonable budget - the Honda would get a Comptech S/C, and the WRX would get a turbo upgrade. I'd expect the slight variance in performance would remain about the same.