As for whether to upgrade the pickups in a Fender Squier, if the guitar is made out of a solid piece of wood, then I would say upgrade because the guitar will get some of its sound from the wood it is made from as well as the upgraded pickups. Upgrading the electronics in a guitar made of laminate board will enhance the sound to some degree. But if you are at the point where you want "something more" in terms of sound from your guitar, you may not get that extra sound out of a guitar made of laminate. Guitars made of laminate board generally don't get a large part of their sound or sustain from the wood they are made of.
I don't make that recommendation in an effort to put down anyone's guitar. I make that recommendation because I have gone through the trouble and expense of upgrading several guitars made of laminate, only to find that the upgrade didn't achieve the outcome that I was hoping for. It turned out that I was trying to get better sound and sustain out of guitars that were never going to give me the extra sound or sustain I was looking for.
I've heard bad things about some high end guitars as well that would make me wary when shopping for a guitar. I know musicians who were really dissatisfied with the craftsmenship in their brand new Gibson Les Pauls. That doesn't mean that they are all bad guitars (I happen to like them myself), but as a consumer, I would take into what I heard from other consumers and give that guitar extra scrutiny if I was looking to purchase it. For what it's worth, I have never had any trouble with any Fender product that I have purchased.
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