First what is the diffrence between the 6 besides the shape. Which one is the smoothest and best player. Which one spins the longest.
iv only tried the 1st one and its pretty good 
They are all good. I like the Second and the sixth the most though.
cool
I have the Zen5 & 6, both play as good, if not better, that throws for twice the price. Well worth the $50!!!
they all play just as well and as smooth, personally i like the shape of 5 and 6 most