Sorry i know this maybe a boring topic I am considering my first macbook pro I buy it just because i want to use lightroom I read some post before, i am planning to upgrade to 16GB ram with 256SSD I want to know the different between i5 2.3Ghz vs 3.1Ghz. Is it huge different if i am not a professional user? I think touchbar is not nessessary for me. But how about 2 vs 4 usb port? I have no idea is it enought of 2 usb port only. If i want to last more year for the Macbook, is it worth to choose the tb version? Thanks!