[barrkel]

I use Emacs copy & paste, or readline. I don't do a lot of copy & paste between different windows though. Paste in works adequately (terminal stuffs it into keyboard buffer) but may need a reformat if the mode has autoindent, while I zoom the window (C-b z) and turn off line numbers to copy out.

If formatting is super important, I paste into a file with cat > file, and read the file into Emacs. I can do the same in reverse for a big copy out, and transfer the file.

I do these things because I often use Emacs in a ssh session instead of tramp, because I'm coming from a different OS or need to use modes with sidecar executables, e.g. enh-ruby-mode.