I looked at one at a gun shop and had the shop owner let me put it side by side with a Shield. There wasn't much difference in size but the Shield gives you a 9MM instead of a .380. To me, the Shield wins.
All things are relative, I guess, and it depends on how picky you are about size. The shield honestly is a little fat for a single stack 9mm, but the gun is an incredible value and if you carry it routinely easily it easy to see why you wouldn't want anything else. The slight pudge-ness of the shield I think contributes to ergonomimcs, too.
For a .380 I gotta say that the Sig 238 is really nice and shootable mouse gun. I'd take it over a Glock 42.
I will give the 238 this much... has to be the lowest recoiling .380 I've ever shot. The G42 is mild, but shooting factory 380 out of the 238 is like fluff mode.
-Mike