Sure.
I removed the original spring and replaced it by one with a smaller diameter. That way the disk that centers the stick has much less friction against the metal stick and moves smoothly over the complete distance (just like the X52Pro).
I also removed the magnet-housings on the X&Y axis and fixed one of the magnets to the part that formerly moved the parts moving the magnets. Less moving parts = more precision, one magnet = linear input.
You can see the effect in the gamecontroller-settings. If you move an unmodified stick, the input values are dampened, so if you move the stick in a circle, the cursor will not make a circle, but a diamond-shaped figure. It's impossible to move the cursor into the corners on 99% of the sticks. If you modify the stick like that, you have a very precise stick and a full range of movement available.
This is how the modification is done:
http://forums.eagle.ru/showthread.php?t=21199&page=7
(It requires a bit of fiddling around and get the right position and facing of the magnets, so you better know what you're doing and consider if it's worth it. On the bright side, though, you don't need any electronic skills and you can easily revert the modification. You will lose guarantee, though, when opening the stick!)