The case is 2mm taller, and actually a tiny bit wider, but the screen feels so much bigger.Aren't the bodies of 38/40 and 42/44 the same size, the screens are just bigger? I had the 38mm and went to the 40mm and the size is basically the same on my wrist, and I have a small wrist. Have you tried the S4 on at the store?
The ‘louder’ speaker was a great improvement, and _much_ needed. Many times with the previous versions of the Apple Watch, I could never hear the notification chime or incoming call in a louder environment. And Siri appears to be way more audible.The cellular/speaker/mic improvements are the biggest day to day things I enjoy outside of the Info watch faces which I do find give me more actionable data than with prior complications - so the glanceable information is just that much better with S4 if you use the new faces - the devs that take advantage of it are doing great things with it