Mine is directly in the middle/top-middle of the soleus and it manifests as a pretty sharp pain deep in the muscle belly. It's sore to touch, and feels like an extreme knot, but massage/foam rolling has never made much difference. The worst time for it is when I drop into a squat before a lift, when I set up on the bar. When I go to raise my hips into my start position it's a stabbing pain that makes me look like my grandad used to when he'd have to get up off the floor...slow and painful
Quint's is the same.
It definitely hurts during a squat, but it's fast enough to not really stop me from snatching or cleaning heavy...it just hurts enough afterward to be REALLY annoying, and makes it much less worth training as heavy as I'd like. The odd thing is that I have great flexibility in my calves, and It's always seemed to me to be somehow related to the combination of the stretch and the impact of my calf/hamstring in the bottom of the lift, as regular front or back squats don't seem to make it happen, they only aggravate it after the fact.