I flew mine for 4 years with a Jet Cap P-160 and AMT Pegasus HP( Full scale finish and weighing in at 18.6 kg dry and it went well. Even at 3000ft above sea level in the heat of south Africa.
I have flown another for a customer with a P-120 but it was a light weight one with no gear doors, No cockpit detail and a light paint finish. This was also good. In fact I thought it flew better ( lighter loading ) I also flew Sandor's with a Graupner booster which I thought was overpowered but fun. So I guess it depends on what sort of finish and detail you want to apply and how you want to fly it ( Sport / Scale).
Any questions feel free to email me direct on [email protected] . More than happy to help
Regards Al