I'm seriously considering switching to the 2015 MBP 15", from a 2016 MBP 13". I do a lot of data analysis in R and writing as a student, and I'm looking to get a larger screen, better keyboard (I get some fatigue in my wrist and fingers after typing for a long time) and physical function keys. Right now I'm torn between waiting for the 2018 release to see what changes, or just get a 2015 now. My concern is that Apple may very well discontinue the 2015 line this year, and I don't want to get a refurb if they do that (I want a new system). Any educated guesses on whether the 2015 will still be available after the 2018 is released?