Has anyone else here ever tried the Smart Joy Frag for the original Xbox? I recently came across it on ebay for dirt cheap thinking it might work pretty poorly with analog->mouse conversion, but I'm honestly quite impressed with how well it works. It takes in a PS/2 mouse and keyboard and emulates the controller, and allows you to save completely custom keybinds to one of 8 memory slots (comes with presets for mostly FPS games). As long as you don't flick around the mouse TOO fast, it performs incredibly well. Setting the triggers to the mouse wheel and targeting with the mouse in Orta feels amazing, and I find myself being able to relax and focus on the scenery and environment so much more. If you have an original xbox lying around, I'd highly recommend giving it a shot.
If you only have a 360, you could always go through the nightmare of daisychaining a number of adapters together because I'm not sure if an oxb->360 adapter was ever done. Now to give this a shot with JSRF and pretend Sega re-released it on PC.