Wood, electronics, pick-ups, basically all of the parts of the guitar can be different in Mexico and American made fenders, depending on model and build date. Upgraded p-ups to Carvin AP11s.....better quack than stock! Bought the tele on a whim cuz I was p/o'd at my then girlfriend!The Made-In-America ones are higher quality, both in parts and build. Fantastic w/sock pickups through a variety of amps. It is the discontinued metallic 'Midnight Blue', my all time favorite Fender color. Now a year and a half later, still loving the tele, plus, now I gotta girlfriend whose not an insane, bipolar psycho!!I have a MIM Fender FSR 72 Telecaster Custom Deluxe with Black Dove P90 pickups (0), and this guitar is amazing. Great construction and finishing, it's at the same level as any other great guitar. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).
At least with basses, the MIAs have also generally had more experimentation with new electronics ideas, such as the S-1 tone circuit which allows you to switch tone cap values with the press of a button.
The Highway-1 series Strats (basically an American-assembled MIM with 70's styling and a few other tricks) did a little of this (my H-1 has Greasebucket tone circuits which reduce the boominess you get when you roll off the tone), but usually when you buy an American Standard Strat you are getting exactly that.
Many people compliment me on the great & smooth sound my guitar has, though different amps as jam sessions.
I haven't had any trouble with it at all, except that I break strings a lot which could be a gnarly moulding on the bridge saddles, or I don't change strings often enough, which is likely.
I've only played a USA strat in a shop as a comparison.
It just felt like another strat, nothing special compared to mine. What differs generally depends on the relative models and relative years.How to date and identify your Fender instruments using serial numbers and production date stamps.No one likes it when you forget their birthday and neither does your Fender. For most of Fender’s production history they have applied serial numbers and production dates that can help you determine their production date (within a few years’ margin, at least).I bought (and returned) 2 MIA strats (one an SRV) for build quality problems.I've since bought a MIM that was better in all build quality aspects but had some part quality problems.Made-In-Mexico ones are still Fender products, and quality instruments. Only change I made was straplocks and a matte black pickplate...looks ultra-retro on arctic white! I have an 1996 Standard MIM Strat (0) and I have to be honest and tell you this guitar sounds cheap and it's miles away from every Fender Standard Strat MIA that I've tried.