I think whether the iGyro or Cortex is "best" is a rather subjective decision as both seem to be excellent gyros and have their strengths. Some may feel the iGyro is best because it uses GPS to reduce the gyro gain as speed is increased, allowing you to run at the maximum gain setting at all speeds. Personally, with my Cortex, I simply flew as fast as possible and adjusted the gain, via a knob, until I could see the model just start to hunt and then immediately backed off the gain a few percent below that point. To be honest, once I adjusted the gain, the plane felt so well locked in that I saw no need to increase the gain at slower speeds. Depending on the plane, servos, etc, others may have a different experience. While I've never flown an iGyro, I've used a number of different gyros in helis and the Cortex works so well, I can't imagine the iGyro being a significant improvement from a performance perspective. So in my opinion, no, it's not just the price, the Cortex appears to be on par with the iGyro from a performance perspective as well.