"G" behavior differs from Vim
"G" implements 'evil-goto-line'. With no argument, this command jumps to the last line in the file. In Vim, the last line is scrolled to the bottom of the window (so the cursor is on the last line of the buffer). In Evil, the last line is scrolled to the center of the window (so the cursor is in the middle of the buffer, and there is a half page of blank lines below it).
"G" with no arguments should leave the cursor on the bottom of the buffer. The "expected" behaviour can be observed now by issuing the command "G zb".