Above is a good example of what LAB is about as far as I can understand it so far. COLOR not saturating colour as in tweaking a dial but colour correction and colour separation. Probably the best area in the image to see colour separation is the horizontal bright red band on the building in relation to the red features in the window posters. The two different hues of red look very similar in the Lightroom export but with LAB the colors are remarkably more defined as two different colors.
Colour Balance, as I look more and more at the original it has a very obvious green cast which is a little more towards the brighter parts of the image. The solid slab of concrete at the top of the window is a good example. With a fancy bit of work in LAB I managed to remove the cast from the brighter areas while keeping the shadow areas relatively neutral.
Another small aspect of the image that LAB fixed up was the color cast in the sky and the overall contrast in the white clouds take a look at the details in the white areas of the cloud subtle but FRICKIN sweet!