hardware-based BC is the bees' knees. Emulation, however, I only see use in when on a handheld. Why would I use a PS4 for emulating PS2 games, when I can do it 5x better on my PC?
As seen by the emulators on my EZFlash cart and PSP, as well as the array of home consoles on my desk, not including a PSOne despite that being one of my main collections.
Maybe I'm just a noob but I always felt like PS2 emulation was a hassle. I'll always keep my original PS2 to play those great imports but it'd still be cool just just play God Hand on your PS4 using the disc.