I've been using large lights for portraits for a while now and I love the way they look. My favorite tool in doing this kind of lighting is the black card I use on the shadow side to make the deeper tones more dramatic. This is a scan from a print and as such it's probably hard to see much detail in the shadow areas but on the negative and in the original fiber based print there's sill detail all the way down until the tones turn black. Difficult to represent on the web with only 255 shades to work with....
My current favorite lighting tool (yes, they change from week to week and sometimes from day to day...) is a 72 inch white umbrella with a black backing that's made by Fotodiox. The image above was done with on of my largest soft boxes used close in.
One of the things I like about portraiture is the ability to constantly experiment with different light sources and modifiers.
When I re-visit portraits like the one above it reminds me how much I like the longer focal length lenses for the style of portraiture I like to do.