I know it can handle only 30hz via HDMI, but since I have no experiences with that I'm asking you what that does mean in real life? I bought the 12" MacBook for maximum portability I can get with OS X and I plan on selling my Windows PC and buy an iMac, but as I am undecided which one it should be and if I should wait for the Skylake 27" update (which might be released in 2 months or maybe in a year, we don't know yet), I wanted to give 4k a try with an external monitor and my MacBook. I know it's far from being the optimal solution, but it is not for more than a year. So I'm asking you if this is usable or too laggy? I won't be doing much more than surfing, streaming videos (1080p is enough, 4k without stutter would be nice) and some light (!) photo editing with small Lightroom catalogues. Is that possible or does the 30hz refresh rate ruin everything?