If you're primarily using one rpm, then timers work Ok. Using various rpms switched back and forth during flight, the flight time can vary dramatically. for instance, at 1750 the entire flight I only get half the flight time I do when at 1250 to entire flight. Yes, it's an enormous difference. That's why i went to telemetry for capacity utilization a couple years ago. Using the sm-modelbau unisens devices. fly however you want, flipping back and forth between rpms, and you get alarmed when capacity is used, rather than some arbitrary time. Flights can go 8 or 9 minutes, or 14~15 minutes,.. and you always know when the "tank" is almost empty
Made reservations for the spring fling. Unless something comes up between now and then, Josh and I are looking forward to it!