I've got Vostro 3550 that I bought to improve my 3D entertainment. The problem is that I feel like I would have bought a computer from 1999 not from 2011. It looks like graphics switching doesn't work at all. There is a proof:
Cinebench OpenGL ratio is almost the same on ATI and on Intel Graphics (on Intel it's even better). What can I do? Driver is in version:8.811.1.5000.
Screen from Cinebench: http://imageshack.us/f/810/vostro3550opengl.jpg/
In the range of notebooks, the Vostro series (now discontinued) were largely rebadged Inspirons - they were for price-conscious small business buyers - which is why you don't MUX-based switching graphics. For that you have to step up to the Latitude series.