I think it's a great idea. And I try to develop a habit of using it. I like the way you can type commands in AutoCad, just type "xr" and enter and the xref dialog opens. But it simply doesn't work well enough in max.
If I for example want to collapse my selected mesh. I press x, start typing "coll" and I see Collapse highlighted at the top of the list, hit enter. And nothing happens. So probably the search found the wrong collapse function thingy and it didn't work. Some times it shows "collapse stack" and that works. It's hard to form a habit this way.