Hi, I am starting my PhD in a few weeks, I am in desperate need of an upgrade. My laptop has finally died after 5 years of service. I will be dual booting Linux and Windows, so a Thinkpad seems a solid option regarding my budget. I really can't afford to spend a whole lot. I will be reading articles, running toy codes, writing, etc. What older models would you guys recommend? I have browsed a bunch and keep coming across; T440 2nd Gen x1 carbon X230/240 Any comment on these three? Even a complete other recommendation is greatly appreciated. Thanks.