It is not well known, and therefore suprising, but the Orion 565 holds a few advantages over the Orion II 566 in terms of performance:

1. The 565 provides stereo line out connections on the Aux I/O connector where the 566 only has a single line out

2. On very strong s9++ signals where the hardware AGC kicks in, the 565 receiver stays clean but the 566 reciever is prone to occasional distortion. This has been verified on three out of three 566's tested.

3. The latest version 3 beta firmware provides a few extra features on the 565 over the 566

4. Some consider the receive audio quality slightly smoother on the 565