Apologies for going over ground covered elsewhere, but I haven't found any conclusive answers for all 3 together. My initial plan was to wait for an upgraded iMac, but the option of having a 5K screen and portability is enticing. Not to mention the addition of an extra screen to work with. With most of my work done on the big screen, I'm thinking of going with a maxed out 13" (with TB). Size-wise it seems just right. But my big concern is performance. Will it power the 5K screen and deal with RAW photos in Lightroom effortlessly? Considering the financial outlay, I don't want to be dealing with any lag or slowdown at all. Anyone got a definitive answer? Thanks!