If I replace the ECU in my EF GLi with the Tickford item, will I see any improvement with no further mods? ATM all I have is a BA air intake.

You will see a slight improvement in responsiveness, and s**t points for the auto, however without the XR6 fuel reg, it will run lean which can cause engine problems long term.
If its going to cost you a bit of $ to do it, then it probably wouldnt be worth it, however if you have the ecu and fuel reg sitting around then go for it.