There is no "iPod classic 4th or 5th Gen". The "classic" line began with the 6th generation of iPod, when the design changed.
As for specific differences in sq, it is what it is. Preferring a wolfson over a cirrus just means that's what you like - it doesn't make the wolfson the better sounding/performing chip.
And Rockboxing a classic (6th Gen and up) truly will bring out the sq it's capable of.
Just because you voted for Obama it doesn't make him any better than Romney. :)