Finally finished my new Stalker 580 to replace my old profile Stalker I've been flying for the last 4 years. 55 inch span, 582 sq inches wing area. Early flights are promising and plan on bringing it to the Nats if I get it all trimmed out. Initial flights revealed an airflow issue over the ESC, so I added an air scoop made from 2 plastic spoons. Worked great.