"Much" better for the exact opposite reasons! The SX necks are too chunky to my taste (not the shorties though). I also find the finish and fretwork better on the newer squires.Please define "much better". I have a Squier Deluxe V along with a handful of SX basses (see sig). I like the SX necks better because they are chunky and I like the finish better. Different strokes for different folks.
So why do I keep the Squier you ask? Simple, it is a wide-spaced fiver so if I ever learn how to slap, I can do it on a fiver. My SX fivers are close-spaced (the 4stringers are spaced nice for slap), nice for normal playing but not for slapping.
Granted I would still upgrade the pickups and possibly electronics on the Squire but I am mucho picky. I'd assume that the tuners on the Squire are better as well, since the SX tuners are mediocre.
I've owned six SX basses and still have a shortie P, shortie J and a shortie Jag. I've owned a 34" J and a 5 string J as well. I find the string spacing on the 5 too tight for my taste.
