All the EyeOne Display-2's are the same hardware, you're getting differing software.
Spyder 2? Pass, POS. The 3 is said to be better, don't know, I've never played with one. But I've had nothing but good luck with X-rite hardware.
What kind of display?
I've borrowed a xrite Display 1 and it works very nicely.
I have a cheap monitor - SOYA.