I got the impression that the video was somewhat discouraging for people looking to try the emulator for the first time. Specially due to 3 things in particular.
- DF folks are extremely nitpicky (that's all right, its their job after all)
- The game ran on an absolute beast of a gaming rig
- They were aiming for a 60 FPS experience in a game that was far from hitting 30 in native HW
My experience with RPCS3 shows me that there is a whole batch of games that are perfectly playable even with low end PC HW. Games not available on PC which should be the main target of the emulator anyway :Odin Sphere, Dragon's Crown, PSN titles like Hard Corps uprising, Fighting games like VF5. Silent Hill Downpour. And the elephant in the room... Demons Souls.
GPU wise, any low end/mainstream GPU like a GTX 970 or RX 570 should be able to run 3D games at 1440p or even 4k. So even a 750ti should have no issues at 1080p. Some games may not scale well beyond native 720p resolution anyway. But to give you an idea my RX 580 is barely stressed when running Demons souls in 4k.
CPU wise i'd say that if you have something like an I7 2600k and up, go ahead and give the emulator a try. 30 FPS with significant drops is how most of the AAA 7th gen console games used to run, so keep that in mind when running the emulator.