For my money, the best combination is X-chocks and a good trailer stabilizing system. Our Steadyfast system and X-Chocks have been very good at reducing movement to the bare minimum. With just the chocks, there is just enough movement to produce an annoying little spring squeak. Lock the Steadyfasts down, and the noise is gone. We did not try a K-P stabilizer...the Steadyfasts are permanently attached under the trailer, so no extra space is needed, and I don't have to fight with carrying a K-P stabilizer out and setting it up.
2010 Eagle 31.5RLDS
2009 Chevy 3500 CCLB Dually Duramax