What Vim features are missing in Emacs with Viper and Vimpulse?

Question

There are important features of Emacs which are missing in Vim, such as the comint mode, and there are no scripts/plugins which can replace them.

There are also benefits of Vim over Emacs, such as modal editing and generally better default shortcuts. However, Viper mode gets me both. Vimpulse also enables visual mode. Unfortunately, no mode can make Emacs work as fast as Vim.

So I mostly learned Vim-in-Emacs. What Vim features am I missing?