tmux is fantastic, especially for remote development. However, you can't change a single pane's font size, nor is it easy to select an entire line of text using the mouse (with vertical panes). Thus I suggest iTerm2 for local development if on a Mac.

If you haven't tried multiple panes with multiple font sizes — e.g., smaller font for logs/compiling/long-running, bigger for editing — then that's a world I don't want to live in. (j/k ;)