There was an interview with a crytek developer in Farsi. I tried searching for it using the wayback machine but, no dice. Thankfully some neogaf dude captured images of the article. This guy did touch on api's a little bit.
Rough Translation of relevant piece: "
As a programmer and developer, which do you consider the best console for working and coding? PlayStation 5 or Xbox X series?
Definitely PlayStation 5.
As a programmer, I would say that the PlayStation 5 is much better, and I don't think you can find a programmer who chooses XBX over PS5. For the Xbox, they have to put DirectX and Windows on the console, which is many years old, but for each new console that Sony builds, it also rebuilds the software and APIs in any way it wants. It is in their interest and in our interest. Because there is only one way to do everything, and theirs is the best way possible."
Original Link:
https://vigiato.net/p/85342
DF talking about API's ps4 & xb1:
"
Digital FoundryDirectX 11 vs GNMX vs GNM - what's your take on the strengths and weakness of the APIs available to developers with Xbox One and PlayStation 4? Closer to launch there were some complaints about XO driver performance and CPU overhead on GNMX.
Oles Shishkovstov
Let's put it that way - we have seen scenarios where a single CPU core was fully loaded just by issuing draw-calls on Xbox One (and that's surely on the 'mono' driver with several fast-path calls utilised). Then, the same scenario on PS4, it was actually difficult to find those draw-calls in the profile graphs, because they are using almost no time and are barely visible as a result.
In general - I don't really get why they choose DX11 as a starting point for the console. It's a console! Why care about some legacy stuff at all? On PS4, most GPU commands are just a few DWORDs written into the command buffer, let's say just a few CPU clock cycles. On Xbox One it easily could be one million times slower because of all the bookkeeping the API does.
But Microsoft is not sleeping, really. Each XDK that has been released both before and after the Xbox One launch has brought faster and faster draw-calls to the table. They added tons of features just to work around limitations of the DX11 API model. They even made a DX12/GNM style do-it-yourself API available - although we didn't ship with it on Redux due to time constraints."
This is just a snippet from the article but, there are more comments here.
As tech interviews go, this one's a corker. Readers of our previous Metro 2033 and Metro Last Light tech Q&As will know…
www.eurogamer.net
These are the ones I remember off the top of my head. If you trawl through some older developer technical presentations, you'll find nuggets in there that hint at it. Since the PS4 days, its been a generally accepted belief that the Playstation Api's were superior and much faster to that of Microsoft's.