Hello fellow Invicta fans. I was hoping to get some answers about these two watches. I have decided to buy my first "hopefully of many" arsenal/octane. But I can't firgure out the differences between these two watches. I know from doing some research there is a difference between arsenal and GRAND arsenal. But from reading the description And looking at pictures from varies sites they seem to be the same. My main concern is buying one and finding out the other is bigger.