That "died" with the DirectX SDK (which last recieved an update June 2010) when the DirectX SDK release cycle was merged into the general windows one AFAIK. It's had several lingering bugs - to wit, OOM issues, D3D11 support breaking on Windows 7?, and issues with managed code (64-bit specific perhaps? It's been awhile...)
Visual Studio gained support for graphics debugging as a "replacement", in what appears to have at least been a complete rewrite of the UI at bare minimum - with some new features and some missing ones, at least for awhile there.
Aside from "DXSDK PIX" and "VS PIX", there's also been "360 PIX" and "XB1 PIX" (referring to the consoles) - all effectively different pieces of software with their own quirks, bugs, feature sets, user interfaces, limitations... there's probably some common DLLs in the mix, but they're so varied in even 'core' functionality like capture behavior - that it wouldn't surprise me if there was minimal code shared between them.
This latest standalone version looks visually similar to "XB1 PIX", but that could handle D3D11 and this apparently can't? Should I call this "12 PIX"?
I used PIX back in 2012 for porting an engine from D3D9 to D3D11, and I'm happy to see that it finally got an update to be brought up back to scratch.
Old PIX used to be a powerhouse, but riddled with inconsistencies with new D3D11 features, and unstable to boot. It was one of those tools you loved when it worked, and hated if it didn't.
Agreed! PIX is really great. I first used it while working on the X360 and I was blown away by the ability to debug a pixel and replay a scene and step through draw calls, GPU state, etc.
I was sad when old Pix was deprecated, and the visual arising built in tools didn't always live up to being a replacement.
In really glad to see it gets a second chance to shine!