I made the same ordering mistake..... removed the complimentary X1, saw the price decrease, then paid full price for the pair. Perhaps Xtreme customer service will allow us to receive the X1 as that was part of this special.
For anyone interested in the X15 program, this is a spectacularly in-depth and visually impressive sim! I did one flight from Edwards up to 200,000+ ft, then landed in El Toro several minutes later. With "Auto Start" cheat, you still get to see all of the checklist items completed in real time in the cockpit, it's quite detailed. It did feel a bit "Evil Kneivel jumps the snake river-ish" without getting into what actually what is going on, but I'm inspired to dig and see how it all works. A rare thing in flight sim I think! Sub-orbital / thin atmosphere flight using gas thrust for control was convincing.....
Pics and further thoughts later...... tried it in P3D only, with ASN and REX soft clouds; very convincing view of earth and weather from 150k plus.