How do I decide between a Spyder X Pro, Spyder X2 Elite and Spyder X2 Ultra?
The best way to find the right Spyder for monitor calibration, is to use the product finder tool on the Spyder website:
https://www.datacolor.com/spyder/spyder-product-finder/
Keep in mind that the Spyder X2 Elite can be upgraded to the Spyder X2 Ultra as your needs change.