I have a late-2013 13-inch Retina MacBook Pro. I am thinking about purchasing the Dell UP2414Q to use as an external display, but I am worried about the refresh rate. My understanding is that using DisplayPort, the 13-inch rMBP can only drive the monitor at 30Hz. Will the 4K display be worth the investment at only 30Hz, rather than 60Hz? Is there a better external display solution for the 13-inch rMBP? Thanks.