For pattern I want a gas engine that is powerful enough for fai, light enough to make weight in a full composite arf pattern ship, user friendly, "EXTREAMLY RELIABLE" and priced right. The zdz40re is the first gas engine that fits this bill to be "AVAILABLE" in our market. yes it has explosive power at 4200 feet and 100 degrees. no longer can you push throttle stick forward and leave it. You will have to focus on throttle management untill you master it. Eventually you will be flying slower giving more time to think and react. Rather than sligshot you will power through the upline stuff and use that power to keep out of trouble when necessary. Once you get use to it there is no going back. There are some new interesting 30-35cc gas engines that should be tested. Running 30% nitro and pushing my ys140L over the edge probably contributed to its below average reliability. My zdz40 runs cool - never gets anywhere near its limit. For me biger displacement and throttle management is the way to go.