Lenovo T14s here (AMD version). Stuff works out of the box on Debian, except for the LTE modem which works after a bit of a struggle. Battery life is better under Windows but I haven't bothered working out why, probably need to set up some power management stuff. Associated dock drives three 1920x1200 screens at the same time as the built-in one.
If you have issues with sleep mode draining like crazy: Update the bios and enable "Linux" ACPI mode, which they claim will destroy windows beyond belief but I haven't noticed anything. Since otherwise s3 (aka deep sleep) is disabled and s2idle might be broken prior to the 5.15 kernel.
Fyi, they pushed a bios update that fixed my battery issues. It's not m1 good or anything but after the update it's average and sleep works correctly without draining it.
