For face portraiture, sure - but to go for 3/4 or full-length body photography it's far too long, and starts getting a bit expensive as well..
I considered that length as well, but they're only really suited to planned shoots as the focus distance starts becoming a problem as well (unless you go with a macro 85+ lens, which could work)
http://www.youtube.com/watch?v=yIPFX2L9Ve8
At 3"10 you see the focal length which through me quite a bit - bear in mind that the 1D is only a 1.3x crop, but that sort of shooting distance is a bit too much for me personally, though it may be different for you
I considered that length as well, but they're only really suited to planned shoots as the focus distance starts becoming a problem as well (unless you go with a macro 85+ lens, which could work)
http://www.youtube.com/watch?v=yIPFX2L9Ve8
At 3"10 you see the focal length which through me quite a bit - bear in mind that the 1D is only a 1.3x crop, but that sort of shooting distance is a bit too much for me personally, though it may be different for you
