Difference between older PS4 models vs Latest

besides the older models having the glossy part and now the newer models being complete matte

what's different about them?

im consider buying a used PS4 for my nephew and I keep running into people selling the older model with the glossy side.. Would i be okay buying that model? what should i look for?

any info is appreciated. thank you

The power/eject buttons are physical buttons instead of touch sensitive. Quieter supposedly. Runs cooler. Nothing earth shattering.