I've noticed with the new DIY style page creation tool that the default image size when you add a picture from SP is medium. So it uses the medium version rather than original or even large. If you click and drag to make an image larger on the new editor it gets distorted and grainy. I've noticed this, so when ever I want a larger picture I go back and use the old editor, find the code, and replace the word medium with original. Works fine, but it's a bit of extra work. However, not everyone knows about this. A good example is the currently featured trip report by MikeLJ A short day out. Great report, but the pictures are a bit grainy. If you click on one however and go to the original they are nice and crisp. They are grainy on the TR due to dragging to enlarge the "medium" image on the new editor.
Is there a reason medium was used as default? Could this be changed to original? I think this would make some pages look better when people don't know about html code and want to use a larger size image.