When the panel is set to Left or Right orientation, the Show Desktop icon is as wide as the panel size (which is typically going to be hundreds of pixels wide), which looks absolutely ridiculous, and is a huge waste of space. Similarly, the tray icons resize to their full size (64 pixels?) and don't pack, leading to the bottom 30% of the panel consumed by the tray, 10% used by the Show Desktop icon, and 100 pixels at the top used by the Menu button which has its text rotated. All of these issues together make using a panel in vertical orientation impractical.
I agree. For wide screens, it's more efficient to set panel to right or left orientation.
But Mate panel applets need some improvements to deal properly with it.
There are the ones mentioned in the above comment, but also :
You can edit the format of time/date in dconf-editor
Thanks for the tip !
"Mark as can be closed"
@stefano-k - Please close this as it is a duplicate of #157.