IMO go with the drop ins and do the modshack DIY vent thing and you have 90% of the gains that the long tubes say they get for 10% of the cost and you dont have to take your bumper off to clean the filters every few thousand miles. I say few thousnad miles cuz once the filters even start to get dirty gains decrease quickly.

They don't get dirty that quickly. Seriously. The way they're located up above the front crash bar and suck in air from behind, they stay pretty clean. Take a look at these pics. I took them just a few weeks ago. Look at the filters. And I have about 6k miles on them. (I had my fascia off to install my oil cooler.)

http://www.the370z.com/members/semte...ilter-view.jpg

http://www.the370z.com/members/semte...-structure.jpg