Just make sure your using the "ELECTRIC" APC props, and not the "GLOW/NITRO" props.

The APC props are far better than the GWS stuff. They have blade pitch designs that are more effecient, faster, less drag, etc.

If your running a GWS, try to stay the around the same size and pitch with the APC stuff. If you have to increase length, decrease pitch. For example if running a 8x4 GWS, and you cant find a 8x4 APC try a 9x3.8 slowflyer APC.