Sample 24 vs. 16 bit

I have a quick qestion in an area i'm getting confused in.

How important is the bit rate of your samples, assuming the kbps are the same is a 24bit sample better than a 16bit sample, would a pro producer release stuff using 16 bit samples in it.

I always valued 24 bit samples better than 16 bit samples, i've always though that a higher bit rate would increase the width of your sample but how much the ear can pick up on im not sure anymore.

Thanks for any help you guys can give