I have the 42mm polar and it looks bigger on the wrist than my newly accquired SD43 although i don't have a wrist shot of that yet.
If i hadn't bought the SD43 this week i was going to buy the Explorer11 in black as it's the most comfortable watch i have worn as it sits flat on my small wrists.
I think and it's hard to explain but the black seems to wear slightly smaller but that could be my imagination.
So although 42mm it looks bigger than my SD43mm that's why i always try before i buy.