Big or small difference in what? Color? Growth?
Some marketed 10,000K lamps can look more white than others, and appear closer to a 12,000K lamp. Your own perception of the color has a lot to do with it as well.
In terms of growth, most people run multiple bulbs with different spectrums so it's hard to say whether or not growth could be affected in the same way that people that run only 10,000K or 12,000K halides would.