I think you mean the Neox 412 vs. the Neox 614.
I believe the 614 is more of a high performance binding. It has a higher DIN range (from 6 to 14) while the 412 ranges from 4 to 12. I believe it's also a heavier binding (in terms of weight on the ski - matters mostly when carrying your skis). Unless you are a real big person (more than 245 ponds I think) or you are a racer that requires a higher DIN, the 412 should be sufficient for most skiers' needs.