here they are side by side, comparing their features
http://www.91mobiles.com/compare/Samsung/Galaxy+Mini+S5570/vs/Nokia/X3-02+Touch+and+Type.html
obviously the main difference is the build of each phone, but if texting is ur priority, i would go with the nokia because nokias always have the easiest keyboards to type with and are really durable to last a long time.
It also has better features overall.
http://www.nokia.com.au/support/product-support/nokia-x3-02/specifications
