Read whole articles. With nothing selected, the reader now picks out the page's main article and reads that, skipping menus, sidebars and ads (#14).
Selections inside iframes can now be read from the context menu.
Screen stays on while reading. The reader keeps your screen from dimming or locking while it's running (#16, thanks @bobrippling).

The reader no longer breaks the page's own scripts (#17, thanks @sheldoncork).
Buttons in the page's own pop-ups no longer stop working after using the reader (#15).
Line breaks with punctuation now respect the punctuation delay setting (#8).
Opening the reader again while it's already open no longer leaves an overlay you can't close.
Pausing and resuming quickly no longer makes the reader skip words.
Keys are only captured while the reader is open, and only its own: typing in the page, or shortcuts using Ctrl/Alt/Cmd, are left alone.
The page's styles can no longer change how the reader looks or cover it.
The highlighted middle letter is correct for words with accents and other non-English letters.
The remaining time no longer shows "0:60".
The reader no longer jumps in height before the first word appears.

The settings page layout no longer has huge inputs with the preview drawn over them in Firefox.
The "Full screen" option now saves, and "Reset to defaults" works.
Invalid values (e.g. empty fields or a speed of 0) fall back to sensible defaults instead of breaking the reader.