I had a Rift for almost 3 years and have been very happy with my switch to the Ody a few weeks ago. A lot more pixels and a sharper more vivid image overall. No need for external sensors and very well suited for flight sim.
Don't forget though that this sale is for the older original Odyssey without the anti-SDE or BlueTooth in the headset. It is a great headset anyway and many like it better due to the display image being "crisper".