I was thinking about something like the P73.
My use case is a stationary and docked laptop connected to an external monitor. I would mostly be using it conjunction with my desktop PC for torrents, watching 1080p videos, and browsing the web.
Being able to have large amounts of storage is nice. The T440P with the disc drive to SSD upgrade was nice for dual SSDs.
I don’t think I really need to upgrade that much but it would be nice to be able to do some light (2010 era) gaming when I travel or have less lag when I fire up GIMP.
Easy reparability, eGPU support, USB C ports, and upgradeability/modability are things that I would consider bonuses but might not be needed depending on the system.
I wouldn’t bother with the upgrade unless your T440P is falling apart like my X220 is. You can put in a 4TB SSD pretty cheaply. If you want to do heavy transcoding or something like that, use a remote server rather than a high temperature, power hungry laptop.