If I may add my pennyworth, my son and I put a GPS in our Super Reaper. On average flying back and forth in front of our runway, our turns were 500 metres away from the pilot in both directions and loops averaged about 350metres high. Our grass runway is 220 metres by 40 metres. Take off requires about one third to one half of the strip. Landings are rarely outside it but the Eurosport, the Hawk, Exocet tend to finish at the far end of the strip. With 14lb engine the Intro can be kept with about 50 mtres. Crosswinds and flat calms tend to put the pressure on. Sorry not to convert the units, (39inches=1 metre approx).

However when push comes to shove a full size runway is much the best!