Re: Why quad core?
"but hardly see the point for a phone or even laptop."
But I travel a lot ( 1/2 the year) with my laptop, DSLR and HD video camera. As 1080p/50 video requires masses of CPU for H264 rendering it took ~50 mins to render 1 min. of video with my old laptop ( admittedly an old Celeron) but now takes 1.7 mins for 1 min with this quad-core i7. That means I can render during the trip and don't have to spend time after. Well worth it if you spot a mistake in 10 mins of video and have to re-render.
And it's still perfectly usable during rendering for stills processing or editing more video.