The chips do some things that can and most likely do increase power but sometimes at an increased need for more octane. Rather than install something that requires you to have your foot in it all the way in order to "feel" the added power, you might consider something like a Remus exhaust system. I had one on our 2004 XC90 AWD 2.5 for basically 135,000 miles, and when we traded it in I had the original exhaust put back on and I have to tell you, I could feel the difference right there and then. You can hear a lot of claims about power for this and that, even cough cough air filters will claim to give you more power, but the free flow Remus I had really did a nice job. It was there at all rpm, all the time, and it sounded nice too, saved some fuel perhaps, cost less than a chip.
P