I can't draw worth beansy, but I could see the difference when I tried writing my name:
http://bryceharrington.com/freehand_drawing.png
Try signing your name with the two apps and see if you notice a difference.
Oh yes. Of course I notice a lot of difference. It's only that the difference is entirely the opposite :)
http://inkscape.org/cgi-bin/wiki.pl?SandBox2
I really cannot understand how you got the results you got, other than by drawing very small and very slow (and I still cannot quite reproduce this no matter how I try). When I draw, using a tablet pen, with my normal speed and normal range (the same as on paper), I get the results shown above. Inkscape reproduces my hand correctly enough, and it's readable. I can also make very smooth curves, as the spiral shows. Sodipodi awfully lags behind, making writing totally unrecognizable, and while it also produces smooth spiral, this spiral is in fact useless because due to the lag, it ended up about twice smaller than the shape I really drew with my pen.
So, to me the comparison is clear. Inkscape's tool is not ideal but is usable, while Sodipodi is a joke (it might be worth considering if there was a user setting to reduce the lag, but there is none). Just use a pen and don't try to cram a complex curve into 50x50 pixels. It's not supposed to be used that way.