I went back to standard after i red some post on here, saying fit standard back on and see if you can tell any difference, so i did and yes i could. Car ran smooth from gear to gear, less lag meaning was alot less harsh going redline ish up the gears. Got about 3-5 mpg more.
As for the holes in your air box, this would increase air intake meaning more noise, but would pull in lots of crap from engine bay air fillter would clog up after just a few weeks.
Put it all back to standard and you will fined a much more smoother car, and safer on your engine and drive train.

 

personally i have had no issues with my VTA had it on for over a year, however the car is still expecting that bit of air back in the syste which it never gets on a VTA so i would recommend a mapping the same goes with air filters but most fit these without do that either. however my car runs a little rich now which is better than running lean.