Re: what the *bleep* has happened to the comments?
No, it's the layout as well as the size. It used to be in a nice neat column in 100% font size, with replies neatly laid out after. Now it's across the whole screen at something like 150%-200% with replies seemlingly taking up twice as much space.
Edit: ah! a bit of experimentation, somehow 'Sort by nested thread' had got selected which makes a right pair of danglies of the the layout. Selecting 'Sort by oldest' does a stty sane.