make undo operate as in (no flames please) vim

[Harry Putnam]

I've used emacs for a goodly number of yrs now.  I'd say though that
my usage is considerably less sophisticated than many users here.

One thing I've actually come to dread is using undo.  I've never taken
the time to get this setup in some way that seems more useful to me.
I always just go for the `C-x u' repeatedly or else preface with some
number (C-u 20 C-x u) to get close if lots of undos are needed.

I often hit `C-x-u' (forgetting to release the C-x part) which brings
me to `upcase-region', which I keep disabled; that means I'm whisked
to a lengthy message about using `upcase-region' and generally
completely disrupting what I was doing.

This is of my own making and not a fault of emacs, but still I'd like
to have the undo behavior I find in vim.  It seems way closer to what
I usually want.  Where I press some keycombo and a whole sentence or
whatever is undone.  Instead of `C-x u' repeatedly to undo the same
line or even paragraph of type.

I don't want to go to viper-mode. That seems a bit drastic, but can
anyone tell me how to setup `undo' to behave more like the undo found
in vim?