I'm not planning on getting the EF-M 18-55mm as a standalone purchase.
Neuro - I do have a couple of copies of the EF-M 18-55 and coupled with the IS is the best "kit" lens that Canon has ever put out. The fit and finish is great, the zoom is perfectly smooth, both copies attach to the camera in the smoothest way. For $129, I just can't believe it. I'd buy another but with the white one I bought for my wife, we have three copies and they are all perfect.
As far a the extra length, it is still shorter than any EF and adapter combination. I hold the camera in the palm of my left hand and my index finger can work the zoom control.
For the $129 price I vote it the best Canon value that I've seen (of course $299 for camera and lens ain't bad either). As an aside I too enjoy the 40mm pancake, the 50mm 1.8, and the 85mm 1.8 using the adapter as well. All five lenses, flash, and camera and minor accessories will fit into a small urban disguise small thinktank bag. My new airplane carryon.