[wollw]

vim will auto complete words if you press control-p while in insert mode.

http://i.imgur.com/tdcEc.png

For what it's worth I feel how you feel about vim, about emacs. I suspect it's just a matter of familiarity.

edit: As DrJ points out, control-n works too. Seems the 'p' is for previous keyword and the 'n' for next keyword.

[pyre]

The "M-x <tab>" that kamaal is talking about is for editor commands. Similar to ": <tab>" in Vim. The difference being that all of Emacs' editor commands (even "move one char to the left") are elisp functions that are available from the M-x prompt.