I think the 310 did the light/power button better than the 910 or (it sounds) like the 920.
With the 310 (at least with the way I have mine set), the display does not light up until you manually hit the light button once. Thereafter it comes on every lap, even autolaps, if you don't hit a button.
The advantage of the 310 over the 910 is that on the 310, when you manually hit the light button, it just lights up. You have to hit it twice to see that light-level indicator. But on the 910, whenever you manually hit the light button, the light level indicator pops up immediately, obscuring the screen you were trying to see in the first place. You have to manually hit the button again to dismiss the light level gauge.
Not a big deal once or twice but when you are running in the dark often,with gloves, trying to hit that button again becomes annoying.
The 910 has that feature in which the display is supposed to come on if you tap the watch but that just barely works at all, I find. Completely useless. You have to really bang the watch to make that happen.
With the 310 (at least with the way I have mine set), the display does not light up until you manually hit the light button once. Thereafter it comes on every lap, even autolaps, if you don't hit a button.
The advantage of the 310 over the 910 is that on the 310, when you manually hit the light button, it just lights up. You have to hit it twice to see that light-level indicator. But on the 910, whenever you manually hit the light button, the light level indicator pops up immediately, obscuring the screen you were trying to see in the first place. You have to manually hit the button again to dismiss the light level gauge.
Not a big deal once or twice but when you are running in the dark often,with gloves, trying to hit that button again becomes annoying.
The 910 has that feature in which the display is supposed to come on if you tap the watch but that just barely works at all, I find. Completely useless. You have to really bang the watch to make that happen.