While back, I started to wonder what exactly Nappa was. Hard to get a clear answer, as it isn't really defined from what I saw online. It's not like it's from a particular type of cow, or geographic region, etc. It's just really nice leather, apparently.
I do notice now, even quite pricey German cars have the fake stuff. Not sure many can even tell. I don't feel the Nappa in Mazdas is of any significant difference to my CRV's plain old leather.
Before the CRV I had a CX7, both with black leather. I chose black to hide dirt but it backfired. My wife is fair skinned so is a big sunblock user. That is much more noticeable on black than any other dirt we would bring in the car. I wanted beige for my CX9 to make for a perfect sunblock camouflage but availability had end up in the Signature with Auburn. Sunblock doesn't show as bad as on black, but still a bit.