I too have one of the Wren 44's, the manual start version, and love it. If your power curve "problem" is what I think it is, it's just the fact that the thrust output from the turbine is not linear to it's rpm. Most of the thrust comes from the high end towards red line rpm. I use Futaba transmitters and on both my Wren and Simjet I have a big, healthy dose of positive expo on the throttle chanels. I reached it thru trial and error over a few flights until I got to where it 'feels' linear on the throttle stick. Afterwards just out of curiosity I checked my Simjet 1200 with the data terminal and full throttle and max rpm is 160,000 and at half stick it's at about 130,000. The numbers may not look right but the proof is in the flying. At half throttle my plane is flying at what feels like half power. Try it and see how it works. If you use JR tx's I think they call it negative expo, not sure though.