I do exactly the same but with X220s. With an SSD and Debian they make a great coding laptop. I buy stacks of them and just move the SSD across when the break.
Also means I can leave one in the office and have one at home then just move the SSDs between them.
That sounds so much easier than what I am doing with my laptop (macbook): I have to put it in my bag somewhere and take it out somewhere else and continue exactly where I left off every time. It is such a burden...
A friend of mine takes that approach, but the T440 has a whole unibody panel that takes a minute or so to remove. The T430 and T410s comparatively have nice little hatches where a single screw will let you pull the drive.
How do you like the X220s? I nabbed one for a friend a while back, seemed like a nice smaller form factor laptop, she rather liked it iirc. Good price too, think I paid $65 for it.
I'm just passing the 6 hour 30 min mark, though my battery is a few years old. Its reporting as 75.8% capacity with 4% left, so another 20 minutes perhaps, gonna throw it on the dock here though.
I've got Atom open, Signal Desktop, Tor Browser Bundle (Youtube), Firefox with a few dozen tabs (Soundcloud, HN, etc). Couple spreadsheets too in LibreOffice, and Thunderbird & Transmission too. With a few of those closed, should be able to get some more battery life, but I don't feel in need of it.
Also means I can leave one in the office and have one at home then just move the SSDs between them.