I always do and most importantly you know for sure that you successfully chambered a round out of the magazine if there is room for one more. I don't do the peeking in the chamber routine.
I load one directly into the chamber then insert the full mag.
Always top off. I typically have an empty mag to load the +1 to the chamber...saves on having to load/unload a mag.
I've also convinced my wife to allow me to leave my EDC loaded 24/7 so I don't have to rotate carry ammo nearly as often.
No. I like to be able to contain all my rounds in one magazine. I cross over into Illinois frequently and don't like unloading my gun and having a loose round.
If +1 was necessary, no one would carry a 1911, would they? Or a revolver?
WWDHD?
Be careful doing this. Most gun manufacturers do not want you to do this because it can damage the extractor. Read your manual. My XDm had in big bold red writing NOT to do this.
That kind of like saying that since the average gunfight involves only 3 shots, you might as well leave half of your model 29's chambers empty.
...I read in some gun magazines 20 years ago that this practice will make the magazine springs last longer. I don't know if this is true or not...
but I figure it cant hurt...