Quick sketches can be useful to remind you of a view. You can think about weather and how rain falls from the clouds over the sea. The jumble of buildings with slanting rooves, hunkered down for an impending storm.
Sketching fast gives you the chance to record something that may be fast moving, capture motion, in fleeting minutes the whole thing has changed!
Apparently both of them are acceptable. One is more modern than the other but I guess it’s what is most comfortable for you.
This is the view from the side window now that the leaves are going. Reminding me that despite having lots of trees in the garden we still do live in a city of old buildings, built of bricks, with a small amount of new buildings going up. Those will have flat rooves (there I’ve made my choice!)