Having been introduced to DSLRs by shooting video, I've used a LOT of live view. While it's an effective way to get focus (I use the LCDVF) there is one BIG problem that plagues me... especially in studio.
LiveView uses the selected aperture instead of using max aperture like you get when you shoot the more conventional way. In the studio, I am often at F8 to F16. Which means under the modeling lights, I can't see ANYTHING. Outdoors in the sun, things are very different.