I assume that has to do with the timing of the shots. These seem to have been taken very early in the morning and towards the beginning of autumn (based on clothing).
Unlike the 360 Cities panaroma, there are far less discontinuities this time, though I have already found a significant one [1]. I guess the almost 5-fold increase in shots is the source of the improvement.
Also, the depth of view in this panaroma is ridiculous! You can actually clearly see individual people playing soccer or walking through very distant parks...
[1] http://btlondon2012.co.uk/pano.html?view.hlookat=-96.8425...