Capa generic disappointment??

[Stattic]

well after changing my cat and fixing the mess the last exhaust place made, my car was going nice and hard. today i decided that i was ready to flash tune as id felt the difference the cat made and honestly i am not really impressed... it doesnt even feel any different! i know for a fact that i flashed it correctly, its really not that hard to do and im worried ive spent $500 on nothing.
i know i will need the box when i get it custom tuned but.... i was expecting a bit of a difference on their tune! the only thing i can tell is that the top end seems noticabley slower. my dad suggesting we flash it back and time the car to a few different speeds and compare to the flash tuned version. im going to do this tomorrow but i think i will give a call to capa anyway. the guy from the local dyno place told me id be very happy with the generic tune, he reckons for my mods it doesnt get much better

is there anything that could be the cause of this? has anyone else had any experience where they are unhappy with the generic tune?