Recently, I am thinking about changing an external monitor for my 13" Retina Macbook Pro (8G/256 late 2013) since the previous 27" 1080 LG is really hurting my eyes. I really need some suggestions on the choice of Apple Thunderbolt Display or a 4K LG monitor (27UD68). I purchased both of them, and need to return one of them by this weekend. For the LG 27UD68, everything is crystal clear like retina display. However, my macbook can only work with a 4K monitor with a 30Hz fps. Is it really bad? I do feel wired with 30Hz fps because of laggy and stuttering , but I don't know if I can get used to it after some time. For the ATD, I don't know what to say. It has been 5 years since it launched in 2011. Does it worth to buy it right now? I have no plan to change my macbook until the applecare expires next year. and I am using this laptop just for studying programming. Thank you very much for your help.