Spoon covered all the bases (thanks for the visual as well). For the type of riding I do and my level of fitness, I've never ridden in my 50/11. Heck, I don't know if I've even gone down to my 50/13. Often times I'm still recovering from whatever misery I just experienced going up said hill to get a decent to warrant such a gear. I'll free spin to relieve some lactic burn but I'm usually ambivalent on setting downhill speed records. I'm a bigger dude so I've got gravity going and whatever free momentum I'll get on the next roller by such a high speed is usually scrubbed by my own physical exhaustion.
I live where it's real flat but I have some real grinders within 20 miles of riding and as a result I can usually do 90% of my usual rides in the 46 ring with the occasional dip down to the 34. To continue on spoon's point the transition is less jarring, it's just a convenience factor.