Baby #1 - about 2 hours from 4cm to pushing, roughly. I didn't have so many VE's so I'm not totally sure. But when I got to the hospital at 9:30 am, I was 1-2, soft and stretchy, I think, and I started pushing around 12:30pm, and baby was born at 1:25pm. Total labour 7 hours.
Baby #2 - about 2 hours again, I think. Total labour 7 hours.
Baby #3 - about 1 hour, or so. Light labour all day, hard labour about 2 hours.
For me, once active labour hits, it really hits! But that's just me, and I know there's lots of variation on that.