I recently sold my 105/2 DC as I found the 70-200/2.8 more useful (equally agreeable bokeh, more latitude for slower shutter speeds, sharp enough, +zoom). The DC is sort of useful, but I found it often tended to make hard points in the out of focus regions harder...which wasn't what I wanted. The most useful thing I could do with the DC was use f/5.6 for sharpness and still have the background smoothed.
Given your crop sensor (and the fact it's a stunning lens anyway) if you want a dedicated portrait lens at that kind of price consider the 85/1.4D. 105 on a crop sensor is pretty unwieldy indoors. I don't have the 85/1.4D, but it's high on my list and there're enough people vouching for 'the cream machine' that you're unlikely to regret it.
If you're doing dedicated baby work, couldn't you get a backing sheet to sort the background?