I've been fairly happy with my Samsung Chromebook Pro on BART in the SF Bay Area -- in tablet mode I watch lectures using VLC, read PDFs using Xodo, and take handwritten notes (often while splitting a screen with one of the former apps) using Squid. And I can always flip it into laptop mode and run Linux via Crouton for Vim, Octave, REPLs, and QOwnNotes. (I use my Android phone to create a WiFi hotspot when needed for email etc.) Everything syncs up over Dropbox using Dropsync. The aforementioned Android apps all run quite well for me.
(I probably wouldn't recommend the Samsung CBP right now - it's a bit old, and Crostini support has been rumored for a while now, but never materialized. Especially if you want LTE. But Chromebooks are at this point pretty good as Linux and Android machines, and the styluses work well for note taking.)