Matlab dll as browser NPAPI plugin

I am a big fan of Matlab normally, but I find it very difficult to make a nice Matlab GUI that feels responsive and pleasant to use. Modern day browsers on the other hand excel at running responsive, pleasant UIs.

Given that my web development skills are pretty up to date it would seem nice if I could write my Matlab gui as a web app, having it make ajax-like calls to a Matlab dll for the heavy lifting. Everything would happen locally on the machine (so it's not a "web" app as such), if necessary the computer could be installed with the full version of Matlab.

From my very initial reading around it seems possible to do this with an NPAPI plugin in Chrome (and other browsers I presume). Have people tried this before, is it complicated, is it worth it? Are there any alternatives I should consider?

I'm running 2012b, though I don't think that's particularly relevant.