So after lurking around and reading different reviews about available software upgrades, I had no other want then the BMW Factory tune itself. I have warranty, I don't want to void it, I don't need a 400hp tune, therefore PPK 1 is perfect for me. Yes, you can get more for less, but then again, not really. Dinan and JB4 offer great stuff, but none keep warranty without sacrificing fuel economy. This is just my personal preference. For those of you who want an easy-going tune for a bit of extra power and refinement, BMW PPK is for you! If you want ultimate power and neck-snapping acceleration, you will probably not be satisfied.
Mine was sold to me for a pretty good deal by the stealership: $855 for software and installation programming. If I were to give one verdict, it would be this: Worth every penny! Face it, $855 is what a regular axle-back costs--and it won't give you 20hp/32trq gains... Not even close!
The software is instantly noticeable and the car becomes much quicker. I used to have a G37 coupe with full cat-back and HFCs, as well as a tune, which did not match up even closely to this. The car becomes more responsive and more powerful in all RPM range. I do not floor my car every 10 minutes and have only occasional enthusiastic outbursts. From going 5 miles an hour to driving on the freeway, your car becomes faster. 1k RPM to 3k RPM is full of new, fresh power for where you drive most. That is my favorite part about it. That is a win. The exhaust note also very noticeably becomes louder, especially within the 2k RPM range, where the exhaust has a deep, thick growl that you had no idea existed in those pipes. I was honestly expecting just a tiny bit of added noise with the software, but the actual result literally puts the sound where it should be! It was the most unexpected part of the whole experience. Freeway pulls in 6th gear are far stronger--there is no reason why I would want to downshift, even, because it has plenty of power for passing and smoking your friends or strangers. 90 MPH surges seemlessly in an instant without even reaching 3k RPM. I love it, personally.
I was skeptical about whether or not the PPK would carry enough power to make it reasonable and "feel"-able, but I can tell you right now: It does exactly what BMW claims. From the first moment of having the newly-powered N55, I did not once think back and say, "well, BMW sure BS-ed on this one!" The PPK, in my opinion, is greatly underrated; it offers more than I could research online, thus surpassed my expectations. To round it up, if you want identical power to the 335iS for the price of just $700 (I am aware of the overboost feature), this is your ultimate choice. The car is much faster--faster than I'd need it to be. This really puts it straight into the Audi S4/S5 range. I am confident that, on a straight run, the Audi would not be ahead.
If you want an exhaust, forget about it, get the PPK first, and only then start your piggy bank for exhaust. The PPK, from an overall view, is a perfect fit for the money, provided the dealer doesn't rip you off. Although even for $1k, I would still do this. Hope this gives you guys who are thinking about it a pat on the back... Get it! It's worth it. The end.