After the discussion about footwear last week I decided to take my hiking boots out for a 5km on the pavement to see how they faired. I think for an average paced walk they are going to be fine but I need more flexibility in the ankles for speed walking.
There is only 1:30 min difference in my km pace between the two but i can feel the loss of flexibility, They might become more flexible with use so I will wear them in a bit.