I think the transparency tiles are not implemented correctly. Instead of increasing/decreasing the transparency level, we should be able to increase/decrease blurryness level. This way, you would have different options: completely transparent tiles (which in most cases look weird unless you pin less than 5 apps on the startscreen), normal transparency and the more you move the cursor, the blurrier it gets. Why? To keep the image in the background distinguishable without disturbing the legibility of the screen. It would look more polished/refined than then basic transparency we have at the moment. Depending on the image you put in the background, you have to sacrifice either legibility or looks. A little bit like what was done in this concept by Moises David Perez Naranjo:
After a while, I find that the basic transparency effect is boring and does not serve its purpose well: adding more pop to the startscreen while being classy/sober. That's just
MY opinion of course. I know that other people like to pin everything on the startscreen they are totally fine with it.