Why? What do they bring to the game?

  • They emphasize the abstract nature of the combat rules.

    This would facilitate the description and execution of vivid stunt-based play by de-emphasizing simulationist concerns of what can be accomplished in a round.

  • They would streamline the action economy.

    Related to the above point, the Move action would no longer be a needed construct of the combat round. In fact, a character's movement speed would only matter when it mattered (in a pursuit, for instance, or a race). A character would be able to traverse most skirmish-scale battle fields in a single round, thereby emphasizing incentive over ability (although, presumably, the DM might still call for checks for style-based movement--chandelier swinging, for instance).

    Additionally, the importance of a grid is diminished, so play without such is easier.

    Similarly, the need for a distinction of Swift, Minor, or Free Actions is completely done away with. Anything that can reasonably happen within a minute can reasonably happen within a minute.

  • They would increase the DM's flexibility in encounter design.

    Let's face it, with combat rounds lasting 6 seconds each, most combats are over far before any reasonable chance for reinforcements could arrive to swing things (that is, any reinforcements that weren't already just on the other side of that door.

    Returning to a one minute round returns an important tool to the DM's toolbox--the ability for DM's to adjust almost any combat with reinforcements, or to set up a combat in waves through use of the same. Yes, these are possible with 6 second rounds, but verisimilitude takes a hit (and, yes, I talked about emphasizing the abstract nature of combat before, but "abstract" and "verisimilitude" are not mutually exclusive).

Any other thoughts on why an option to return to one minute rounds might be desirable?