You're exactly right and that's the exact reason I wouldn't get a 911 turbo over a gallardo. The entire series looks the same and unless you know cars, you won't know the diffs.
That said, yes the 4/4s design works, but a more drastic change was in order. We got screwed on the 4s that was said to be an upgrade. The internal changes on the 5 are cool, but face value, the phone looks the same and most people, like me, wanted more of a physical change. Design is just old.