So, Ive got the stock 1.3 ghz 512 model (2017) and having doubts on this choice. I can return it and get a CTO. Im willing to spend money to a CTO maxing to i7 dual core and 16 RAM if there is likley to be a tangible increase. What I use my laptop for. 1. Read big file PDF's (medical textbooks). Some of these go up to 1500 odd pages. Occasionally highlight text. 2. Read lots of other PDF's, medical documents etc. (also highlight) 3. Safari, iTunes, Mail etc.. 4. Create and read powerpoint and Word documents. Not overly big, about 50 pages on average with images etc.. That is about it. My biggest concern is RAM. So far, according to my usage patterns, it seems to leave about 2 gig free (using about 6 GIG). Is the 290 dollars worth the future proofing? Secondly, is that when I scroll through PDF's on my Desktop Mac, or my previous 2016 MBP), I get zero lag or stutteryness. Its a bit more pronounced in the MacBook. Would the Ram and CPU upgrade resolve this? Thanks.