I have tried@ 8 plug and play programmers and chips. Over the last 25 years. They were all a disappointment. I didn't feel I got what I paid for. Sawyer tuning came through with this ST-10 Stage 3 chip. The performance you get for the money you pay, is well worth it. The power, torque and performance you get with this chip is in your face noticeable. This chip has two beefy boards. I tested it to see if it is really communicating with the ECU. All pins are active. Chip is effectively overriding the stock tune with the performance tune. Has Bluetooth for live data engine performance apps. ST-10 is always on, even when the car is off. It uses a good amount of juice. It will kill your battery, if you don't unplug it daily or you don't drive your car for a couple of days. I left it plugged in & had the Bluetooth on. It killed my battery in about 14 hrs. It took it from 12v to 6v. The car wouldn't start. I bought a new OBD2 cord for it. With an inline on/off switch. That way I don't have to remember to unplug it every night. I just flip the switch off at night. Then on when I drive. Sawyer contacted me after my purchase. They asked what mods I had done and some engine info. (Infiniti G37) So they could tune it to my specific set up. That tells me it's a custom tune. It will also notice new added mods and adjust accordingly. Not like some that say it's custom, but it's really a generic tune for all cars. One size fits all. Some are just light scams and do nothing. This chip is legit and worth the money. Communication is on point. They always get back and answer all of your questions. Even a year after your purchase. I noticed a difference quickly. More low end power, Torque, HP,. Ecceleration, smooth shifting. Good gains all around. While using premium gas performance is even better. The chip recognizes what fuel your using and adjust to it. Sawer has a econo gas saver/low performance tune. I have the maxed out performance who cares about gas tune. Overall I am happy with the purchase and performance gains this chip delivers. It outperformes a lot of expensive $300-$600 chips and plug and plays. The tune you get for the low price you pay, is well worth it.