If I handed one to you, and didn't tell you it was a four cycle, you may use it for weeks, months, perhaps longer, without knowing. I know this to be the case -- people having bought 4-mix products, and used it for a long time without realizing. Yes, the audio is a bit different, but can easily be missed. A user may realize it does not use as much fuel, but maybe not. They may realize it starts easily, but may just attribute it to being a new unit. People easily move from a candy-bar cell phone to a flip phone. Then they move to a screened phone. Soon, they move to a smart phone. And, then move to a tablet computer, getting e-mail, processing credit card transactions. All these changes seemed to be in stride, although the changes are very significant. Yet, when having a handheld with a new name, but doing the same task, the antennae of disruption rises high.