So in a typical use case, here I am opening a Excel spreadsheet remember which worksheet, which row and which column I’m working on. Next to the Excel spreadsheet I have my browser with three tabs open,and now I’m looking at the E-commerce backend to verify the amount in the spreadsheet cell. Oh wait I need to verify the customer’s address in our proprietary CRM. Then I have to go to the start screen to launch it.
The bad news starts here. The start screen takes over the desktop, presenting me a screenful of flat icons, now my brain’s context switches away from the Excel/Worksheet/Cell, amount, browser and customer detail to verify.
As the tiles are shaped similarly but they might or might not look the same (Live-tiles), you now switch to a tile hunting mode, your brain now loads whatever it needs to help you hunt for the tile.
When you’ve successfully found the tile and launch it, now you are brought back to the desktop or not if the application runs on the RT runtime. Your brain would now need to reorientate to the desktop and remember what you were doing before being switched to the start screen.
This reorientate process is a tedious task as you need to recall the application that was loaded, where was it, which portion of the data was your concern etc. Even though all of the above process takes place in a matter of ‘one/two seconds’, it is enough to make me be unproductive with the Windows 8 start screen.
In conclusion I think that making the start screen background the same as the desktop background wouldn’t help much due to the context switching that is involved when the start screen takes over the desktop.
Maybe Microsoft should make it so that when Windows detects that it is running on a laptop without touchscreen, have the start menu enabled. If it’s a detachable then have the start screen and start button when the device is detached as a tablet.