i think if its a daily driver, then -7's would be the best choice, however if more like a weekend car, -5's... purely because every time that i want to jump into it, i feel that its going to be much quicker when boost comes on and you would enjoy that rush more so! thats why i bought the -5's over the -7's! and yes, i am very happy with them! i have been in an identical gtr to mine but with -7's and can say i do not regret what i did... also, it comes down to if you have future plans for the motor, these turbos would be a great investment should you have to rebuild your current rb26 and not having to worry about spending another 2k + on turbos at that time.