Saitek has drivers for the X52. I have one from 2002. I expect that the X52 output tailors to the X52 driver and same for the xbox.
https://www.pjrc.com/teensy/rawhid.html
If you want to create a custom application, Raw HID is simple way to send 64 byte packets between your code on the Teensy and your application on the PC or Mac.
HID works automatically with built-in drivers in Linux, Mac OS X and Windows, so users will not need to load any drivers. Your application can detect your Teensy running your customized Raw HID, so to the user everything "just works" automatically.
You can send up to 1000 packets per second in each direction. The USB host controller will reserve USB bandwidth. You are not required send all packets, but if you do, you are guaranteed to be able to transmit the number of packets per second your code specifies, even when other USB devices are active.
How did you miss that?