There's a little real-world perspective in a very recent issue of Cyclist. One of the editors did a ride report on the AlpenBrevet. Can't remember the specifics, but the thing is a semi-competitive sportif, some 270kms with one hell of a lot of climbing.

The writer used a Giant Defy Advanced SL w/Dura Ace and discs, but switched out the drivetrain to SRAM Force 1x11 ... just to see. Perfectly suitable, in his experience.

I don't really see the point in a conversion, but were I considering a new bike I'd be intrigued by the inherent simplicity of 1x11 for all-round road riding.