Old fart when you finally work up enough intestinal fortitude to truly fly a duration model please turn of your pace maker as the "enjoyment / terror" of the first 30 seconds of flight has been known to cause heart palpitations and the rest of the flight (assuming you are good enough) tends to cause a degree of relaxation (around 30 minutes plus if you are once again doing it right) that tends to bring on a degree of relaxation (unless you are in a competition) that truly has to be experienced. The models have to be built, tuned and lastky flown and as such present a challenge that most modellers are not up to. Mind you I am certain you are up for it but can you meet it. Try it and see what you think and as an aside I made a lot of money of young bucks with the challenge " 1 minute engine run and last one down takes the money". Catch ya.