Stopped at lowes by work today. Looked for the 6ah batteries. They didn't even have them on the floor. Had to ask the tool guy where they were, in top stock. They are similar in size to the flex volt batteries. They are about a 1/4 to 1/2" wider and 3/4" or so longer. I do not like the graphics, should have stuck with the same 20 volt graphics.
Dewalt has too many 20 volt battery options in my opinion. 2,3,4,5 and now 2 6ah options. At some point theyou are going to have to drop one or more sizes.