Each of us has his or her personal tool chain. Depending on your job role, the tool chain will look different. My personal tool chain does not have changed much over the last few years, but if I added or removed a tool to my tool chain, this change was often influenced by other peoples tool chain.
My primary work device is a Lenovo ThinkPad X250 (Intel i5 5200U, 8 GB RAM, 250 GB SSD) with Windows 10. I’ve added a 6 cell battery, so I have ~ 95 Wh of battery capacity. This gives me ~ 16h of battery lifetime with my common workload. The 12,5″ screen seems to be small, but it’s okay as I have two 24″ displays at the office. It’s small, lightweight, long battery life and powerful. I awaited the new Lenovo Thinkpads, that were presented some day ago on the CES. But Lenovo removed the Ethernet port on the X280. So this is not longer an option. Maybe the T480 with an additional 72 Wh battery… Devices and accessories are safely stowed in an Eastpack Floid Ash Blend2. It’s a great backpack, light and not too big.