Yeah. By default, the Win7 start menu shows 10 most recent apps, then if you click "all programs" it shows a couple dozen little icons (about 1/3 of my menu) at once. If you have to scroll around to find little things, it takes longer than just looking at a single static page of larger icons.

Well I use the start menu quit often, but almost never the "all programs", maybe I'm not the one.

Also I think the "start menu" argument encompass in reality the whole concept of Metro against traditional desktop UI.

If you don't remember the XP/Vista classic start menu, it's a linear list that expands to the height of the screen (and it takes multiple columns if the height isn't sufficient); no scrolling, no (or limited) two-dimensional scan. Even better, the list can be sorted for fast searching.

It's a good question because there are a handful of variables at play. Size of the window, density of objects, the layout of objects, the ordering of objects, etc.