[arokh]

How is 23.976Hz? Has anyone verified using MPC?

Honestly I can't see the difference from my Ivy Bridge NUC, but I haven't looked side by side. 24p playback is smooth as far as I can tell (my TV supports it @ 4x24 = 96Hz). What's MPC?

How noisy is the fan during playback?

I'm noise sensitive, it's inaudible during playback. However, the fans ramp up during heavy load and can be noisy depending on your BIOS settings. The CPU runs hot so if you let them, the fans will make noise. You can ignore heat and tell the fans to spin as low as you want though.

Is the i5 good enough for dolphin with it's HD5000 graphics?

Haven't played around with dolphin though, but I can use all libretro cores with opengl shaders (including PSX/N64). My i5 Ivy Bridge NUC wasn't performing well with LBA2 in Dosbox, the Haswell NUC runs it perfectly even with shader applied.

Not sure how much power Dolphin needs but I believe this thing will handle anything you throw at it with regards to emulators. I believe the HD5000 is capable of playing CS source at decent speeds, so it's pretty fast. The MBA has the same Haswell CPU so that's a somewhat good reference.