I have to say I miss having an RJ45 Ethernet jack on so many laptops now.
I know dongles work, they're fine, they're just... dongles. A cludge IMO. The issue with thinness was solved long ago with those ethernet jacks in thin laptops, the bottom of the port being a spring loaded flap that accomodated the relatively large RJ45 connector clip.
I've never seen a machine so thin (at its thickest point, usually towards the rear) that it could not use one of these spring loaded jacks that we used to get but I guess there just isn't the demand for ethernet there once was since the opportunity to stop including them seems to have been jumped on across the 'ultrabook' segment.