@sgiacomo posted a NBD thread about his American Performer, it can be found here:
NBD: Fender American Performer Precision
In that thread, he, @DoctorZee, and myself all agree on how comfortable the Performer series bass is, especially compared to a MIM Player Precision. And I would swear the Am Performer is thinner. So I brought my calipers home from work yesterday and this is what I found. The results surprised me.
First, I want to talk about the contours, they're harder to measure, so I left those out. The belly tuck on both basses is pretty deep, the forearm contour looks deeper to me on the Am vs the MIM, but that could just be the difference in the way the eye perceives a gloss sunburst vs a satin lake placid blue finish. And I would also expect some variations in the thicknesses due to the high gloss of the Player vs the satin finish of the Performer.
So here are the two basses in question
2019 MIM Player Precision (High gloss)
2019 Am Performer Precision PJ (Satin)

First measurement I took was the P Pup position itself
Both basses, from the neck to the neck side of the P Pup is 3.75"

Next measurement, upper horn, from the top side of the horn to the neck side of the horn, at the 15th fret.

Player Precision - 69mm
Am Performer - 71mm
Body thickness, upper horn, 15th fret

Player Precision - 42.15mm
Am Performer - 42.65mm
Body thickness at the rear strap
Player Precision 35.5mm
Am Performer 42.5mm
The Am P is 7mm thicker on the butt end, hmmm.
Body thickness at the back half of the P pup.

Player Precision 41.88mm
Am Performer 42.5mm
Body height from the bottom of the bass, across the middle of the back half of the p pup to the top of the bass. Remember the P pup is the same distance from the neck on both basses.
Player Precision 12"
Am Performer 12.25"
And last but not least, width at nut

Player Precision 41.2mm
Am Performer 42mm
So my conclusion. Although there are some slight differences that could just be me and not being exactly on it in my measuring, there's some that are too different to be anything but the fact that they are actually different.
Example the body height from top to bottom across the back half of the P pup is a 1/4" different meaning the Am Performer is actually taller from the top side to the bottom side of the bass.
And the body thickness is 7mm different behind the bridge at the rear strap button, again the Performer is thicker there.
All of this leads me to believe that the body of the AM Performer is slightly bigger than that of the MIM Player while I was totally expecting the results to be the opposite.
Anyway, hope you enjoyed this dive into is there any differences in a Am Performer Precision body vs a MIM Player Precision body? I still can't answer why the Am Performer feels more comfortable than the MIM Player, but in the end it doesn't matter, I enjoy playing both.
And for me, while the AM Performer is a more comfortable bass than the MIM Player, I paid retail for the Performer, and spent money upgrading stuff on it. Whereas the MIM Player I took in on trade for an American Peavey Fretless that I had very little money in. And it came with a FCS 62 P pup and Hipshot drop tuner already installed.
So for the money, my MIM Player was the better deal between the two. So much so that while I took it in on trade with the intention of reselling it to recoup some of my money spent on the Am Performer, I never listed the Player for sale. That was back in October of 2022. And every time I think about doing so, all I have to do is plug it in and play it and the idea of selling it goes right out the window.
NBD: Fender American Performer Precision
In that thread, he, @DoctorZee, and myself all agree on how comfortable the Performer series bass is, especially compared to a MIM Player Precision. And I would swear the Am Performer is thinner. So I brought my calipers home from work yesterday and this is what I found. The results surprised me.
First, I want to talk about the contours, they're harder to measure, so I left those out. The belly tuck on both basses is pretty deep, the forearm contour looks deeper to me on the Am vs the MIM, but that could just be the difference in the way the eye perceives a gloss sunburst vs a satin lake placid blue finish. And I would also expect some variations in the thicknesses due to the high gloss of the Player vs the satin finish of the Performer.
So here are the two basses in question
2019 MIM Player Precision (High gloss)
2019 Am Performer Precision PJ (Satin)

First measurement I took was the P Pup position itself
Both basses, from the neck to the neck side of the P Pup is 3.75"

Next measurement, upper horn, from the top side of the horn to the neck side of the horn, at the 15th fret.

Player Precision - 69mm
Am Performer - 71mm
Body thickness, upper horn, 15th fret

Player Precision - 42.15mm
Am Performer - 42.65mm
Body thickness at the rear strap
Player Precision 35.5mm
Am Performer 42.5mm
The Am P is 7mm thicker on the butt end, hmmm.
Body thickness at the back half of the P pup.

Player Precision 41.88mm
Am Performer 42.5mm
Body height from the bottom of the bass, across the middle of the back half of the p pup to the top of the bass. Remember the P pup is the same distance from the neck on both basses.
Player Precision 12"
Am Performer 12.25"
And last but not least, width at nut

Player Precision 41.2mm
Am Performer 42mm
So my conclusion. Although there are some slight differences that could just be me and not being exactly on it in my measuring, there's some that are too different to be anything but the fact that they are actually different.
Example the body height from top to bottom across the back half of the P pup is a 1/4" different meaning the Am Performer is actually taller from the top side to the bottom side of the bass.
And the body thickness is 7mm different behind the bridge at the rear strap button, again the Performer is thicker there.
All of this leads me to believe that the body of the AM Performer is slightly bigger than that of the MIM Player while I was totally expecting the results to be the opposite.
Anyway, hope you enjoyed this dive into is there any differences in a Am Performer Precision body vs a MIM Player Precision body? I still can't answer why the Am Performer feels more comfortable than the MIM Player, but in the end it doesn't matter, I enjoy playing both.
And for me, while the AM Performer is a more comfortable bass than the MIM Player, I paid retail for the Performer, and spent money upgrading stuff on it. Whereas the MIM Player I took in on trade for an American Peavey Fretless that I had very little money in. And it came with a FCS 62 P pup and Hipshot drop tuner already installed.
So for the money, my MIM Player was the better deal between the two. So much so that while I took it in on trade with the intention of reselling it to recoup some of my money spent on the Am Performer, I never listed the Player for sale. That was back in October of 2022. And every time I think about doing so, all I have to do is plug it in and play it and the idea of selling it goes right out the window.