I was just curious as to how many people here have tried this, given that an HD remake of the Saga games probably isn't very likely. Anyway, I am working my way through the first Xenosaga now, as I finally got this emulator working properly on Linux (it's a piece of cake to set up on Windows, though, so don't be intimidated). My graphics card is only an NVIDIA GTX 660, but I was blown away at the improvement. It really makes Xenosaga look like an early PS3 game, and upscales to 1080p quite well. You will need a pretty spiffy processor though, something in the ballpark of 3.6 ghz. Check out this clip:
https://www.youtube.com/watch?v=pj7XxpLSUtk
http://pcsx2.net/
https://www.youtube.com/watch?v=pj7XxpLSUtk
http://pcsx2.net/