I'm sorry you don't like the X52.
I bought my own as "broken" from ebay, because of the same failures described here. It took me 5 minutes to fix them.
As described by swiss, you can simply fix the magnets on the parts connected to the stick and remove the slider it's originally positioned in. With this simple and easily reversible modification you can eliminate the sloppy center as well as the non-linear input of the original stick design. Precision is perfect after this mod.
The second problem is the centering spring or rather the plastic part underneath, which is cause of the problem. You can easily fix this as well, either by clamping the spring, if you want less resistance anyway, or by adding a second, smaller spring like it's done in the pro-version or simply by using plastic-grease or silicone-spray to decrease friction between the moving plastic part at the base of the stick and the base of the stick.
Yes, it's a pitty these things don't work from the beginning. On the other hand, you'd be a lot more upset about other joysticks with similar defects but tripple the price
I most surely like mine, especially for games like IL2 and RoF.