Having two guns of the same caliber for compatibility issues is overblown IMNSHO. You will have MUCH more fun at the range with two cals. Now, there is no question that the 26 is the best EDC of all of them. I cringe when I see the 19 recommended to so many first time Glock buyers. While it is no doubt a great pistol, its a 'tweener which means it is good at a little bit of everything but doesn't specialize in anything. Think ahead to what your ultimate collection may look like. It is simply more useful to buy the full sized models and sub compacts and skip the compacts unless you KNOW beyond a shadow of a doubt that that is the only Glock in that caliber that you will own.
:goodpost: The great thing about the G30 is you can easily make it into a 21 for HD and yet you can also carry it if you want to carry a .45 for whatever reason.If I could do it again I would have bought a G21SF for home and a G26 for carry. Now that I already have the G19 I fell the need for a smaller ccw and more powerful home defense. Not sure what Im going to do. Its either going to be a G26 or G30 (or) a G26 and G21SF.