. . . on my wrist:

Just a millimeter wider than a 910 Flightmaster . . .

. . . but even with its additional bulk and volume, a 910 doesn't cross the personal comfort threshold.
Curiously enough, a 911 with the same nominal diameter . . .

[mrsnak's 911 on my wrist]
. . . is just over the line, which I attribute to its specific physical attributes.

Amazing how minute differences can transform our perceptions of a watch's presence on our wrists.
Art