11-46 cassette with 48 chainring for commute bike I'm building a new commute bike.  Would like to consider the idea of using single chainring with 11-46 cassette.  Looking at the ratio, 48 front with 46 rear should give me the climbing option I need.  What is the disadvantage of this setup vs 2x11 or 2x10?  

I'm getting similar overall range. There are big jumps, but that doesn't bother me as much.  I'm thinking the catch would the shifting experience. (i.e., shifting with 11-46 cassette might not be as smooth as 105's 11-34)   Is that it?
The advantages of 1x11


11 fairly evenly spaced gears
Can use narrow-wide chain for decreasing chain jump.
"lighter" by some small amount
mechanically simpler


The disadvantages


Gaps between gears are larger than on a 2x10 or 11 
you need a really big back cog for low gears rather than having a smaller secondary front chainring.  This adds weight and its at the back.
You need a fancy rear derailleur capable of handing all this spare chain.
This all increases cost.


I believe theres a 10-50 cassette in the sram line now - marketted as "Eagle"