Wotjek,

Look at the performance of the 'stock' EDF planes that are offered. The vast majority of them have bare minimum power systems, and the ducting is quite 'dirty'. Just by cleaning up the ducting, I've been able to avoid purchasing upgraded power systems. And, for the most part, the stock EDF planes have great difficulty lifting off grass; they are hard ground or asphalt/concrete only runways. Clearly there are exceptions; e.g., the Habu.