> Just a simple example is that in xptemplate (and probably any respectable snippet plugin in vim) you can type a part of a snippet name, hit TAB, and it will expand the snippet whose partial name you typed (assuming there's no exact match). In yasnippet, you have to type out the full snippet name before it can be expanded. This is pretty annoying, especially for long snippet names.

Yes, you can do that as well. See the list of expansion methods with screenshots inside: https://capitaomorte.github.io/yasnippet/snippet-expansion.h.... You may interest in minibuffer prompting.

You already have a built-in template system in Emacs called Srecode that allows you to program your templates: http://cedet.sourceforge.net/srecode.shtml

According to the homepage, "the core template text is based loosely on Google ctemplate".