I only browse and do emails- no heavy work. I have the chance to buy someone's mint-mint 13" MBAir, it's a 4GB SSD and 2011 model, and I'm wondering if I will notice a difference in internet surfing between that and a 2015 MBAir, which those come with 8GB of RAM and also probably a different SSD. I only go on forums, do research, that type of thing.... using wifi from an iPhone hotspot. Anyone think (or know) if I'd notice much of an improvement if I paid the extra $$ to get a newer MBAir? Thanks!