Buying a new gadget online is never easy. Unless you have held something in your hand its difficult to really get a feel for the size and weight. When you are spending a lot of money on a new camera you want it to be perfect so how do you know what to buy?
Check out this new site Camera Size where you can compare cameras against any other camera. This is incredibly helpful when making a new purchase.
One issue is if you are upgrading from a fairly old camera it may lack that comparison. But it will give you a great idea of what most new cameras look like side by side.
Give it a shot.