Hello there, I guess you've seen this post many times in the forum but all I found is about different models. I'm looking for an external monitor for my rMBP with the same resolution of my mac (I don't want to sacrifice resolution). In the about my mac display section, it says 15.4-inch (2880 x 1800) Intel Iris Pro 1536 MB. what is your recommendation? 4K @ 60Hz, 24" or 27" (27" is better/preferred)? thanks a million in advance.