Tested on my 2009 Mazda 6 GH 2.5L , millage: 103,800km. The very last time i did the decarbonizer was since millage in 60k~70k by using threebond.

Results:
1) Engine noise apparently getting lesser,can feel the differences from the driver seat
2) Vibration lesser from Steering and car body
3) Rpm getting stable! it wont simply drop down and raise up in sudden again while in idling.
4) Engine become lighter and more powerful while acceleration.
5) About fuel consumption..... don't know yet, just done the DIY in couple hours ago, so still under observation.

Overview:
The product is cheaper, bottle content is bigger than threebond & 3M, easier to DIY, and one bottle is enough for two vehicle. For my case, one bottle is enough to do on my Mazda 6 and Perodua Viva. Secondly, the seller is very friendly and patient enough to explain the products and telling whatever that i need to concern about when DIY'ing.

Last but not least, Thanks Alan....it's really a great product..... I will spread the "poison" to my Mazda club buddies soon ........and also i will purchase another bottle again for my next self servicing so to keep my engine always fresh and powerful.