Seems like the bike manufacturers are treating 1x as an upgrade to 2x. So for example as you go from a Trek Remedy 7 to 8, you go from 2x to 1x. Same with the Remedy 7 to 8.
They want me to pay more, for less, and I don't think I like it!
I have not ridden 1x, but it seems to be that 2x offers the great advantage of dumping to granny real quick, or hopping to overdrive real quick, without going through a whole bunch of cogs on the back. Am I silly to think this?
This has been my experience, it makes for a quick bailout gear, so the bike actually gets used as a 2 spd. for trails like Sticks and Stones where I'll run big ring on the way down, and granny on the way up. Same cog in the back. It means having a well tuned FD, but once that is nailed you've got it. Or get a thumbshifter.
I like that the rider has more control over the chainline, which helps avoid broken chains and improves efficiency.
Mind you I'm still running an old school splined internal cup BB with a 22t granny, so what do I know?
I guess another plus is that any weight penalty of the 2x is offset by the smaller rings on the cassette.
For certain I know that it's a hella' lot cheaper.
You can replace a whole XT 9spd drivetrain (including pulleys) for pretty much the cost of one NW and a 42t sprocket.
YMMV