Nothing turns me off a gallery faster than clicking on a link and finding enormous images. In fact I make a point of not visiting those galleries any more. Though it's not difficult to change the size at which you view, it is annoying when you are clicking through a lot of images and don't want to keep changing the viewing size.
So, before you decide to join the PaDders, please learn how to resize. There are lots of other advantages including using less space, and less likelihood of someone taking your images if they are smaller too.
Whilst the image size is going up with each new camera, it's more important than ever to learn how to use that piece of software that came with it.