Review: Arc Hub USB-C Adapter
August 2017 update: I just noticed the tech specs on the Arc Hub product page have changed to read: "Arc Hub comes with 1 x Mini Display Port 1.2. Capable resolutions are all HiDPI resolutions, 1080p@60hz, 2560 x 1440 @ 60hz, 3840×2160@30hz." The tech specs used to mention 4K at 60Hz ?.
I've since switched to a CalDigit TS3 Plus and couldn't be happier!
original tl;dr: A capable hub, with some slight design flaws. However, not yet recommended if you want to use it with a 4K monitor, due to compatibility issues with higher refresh rates.