My figure of 6 minutes to walk from the carpark around to WHSmiths can be verified on google maps. And seems about right to me.
It is surprising but we forget how the road curves.

To get from start of Waldenshaw Rd to the All-in-one in 4 minutes via the S. circ is possible if you run all the way and somehow both crossing lights are in your favour. That must have been fun.