> Do you use both the internal display and external monitor?

Yes

    > Have you tried connecting more than one external monitor?

Never tried. This laptop has only one mini DisplayPort output. I heard that there are splitter cables/adapters which should allow for that but I haven't found an affordable one yet. An alternative would be a display that supports daisy chaining (the only one which I am aware of is Apple's Thunderbolt display which doesn't even turn on for me).