What do you see as the benefits that made you want to do this ?
What if I want to view a number of the properties panels while I’m modelling. This would take up a lot of the 3d viewport. Why do you believe this is an improvement ?
How would this work with multiple monitors ? If I want to put the properties panel on a second monitor
Your properties panel has a scrollbar. Does this mean there are more things hidden to the side. My mouse wheel scrolls vertically so easier to scroll up/down to show hidden data rather than scrolling from side to side.
Most monitors nowadays are wide screen, wouldn’t the best useage of space to maximise the viewport favour vertical panels rather than squashing the viewport from the top