I've heard the clock referred to as the 33rd piece in a game, and its status does affect the moves that are made. It would be great if when games are played back the time on the clock could be displayed as well, showing you the time that each player took to consider their move etc. It would then also be possible to replay blitz games in real time, adding greatly to the drama.

I appreciate that this is a big ask (change in PGN format - perhaps a tagged comment added to each move ?), but it seems that this is an important missing element to saved games and chess.com could lead the way here.

Seconded.

Thirdonded.