personally, if i were to get a new quad, it would be a predator. ive rode a piped z400 before, didnt really feel too different then my piped 400ex (mine had a full HMF, his had a slip on HMF).

 

I can't believe you didn't notice any difference between your 400ex and the z400.

I like the 400ex, it's a nice machine, but my z400 is much quicker than the 400ex's I've ridden. I rode a 440ex that was real quick, but then again 40cc extra is a nice chunk of power.