I estimate that I have played fully through JKII at least 20 times ( at least 3x on my original Dell laptop, 7x on my Inspiron 8200, 2x on my dimension desktop, 2x on my Mac Tibook 1GHz, 1x on my Mac AlBook 1.25GHz, 5x on my Inspiron 8600, and that's just what I remember)
In general it still takes me ~20 hours or so to play through. The first time it took at least 25 hours.
I don't play games like that for speed, but for enjoyment.
Dopelar effect (n.) The tendency of stupid ideas to seem smarter when they come at you rapidly.