Visually the wall is very nice and asymmetry and i saw a lot of 3D drawing using this concept with a lot of different size of boxes in and out.
But practically, it is hard to maintenance, even harder if the feature is high.

ya i know, nicer the design, higher the maintenance needed.

haha, you are welcome.
Just for sharing, since you are talking about feature wall.
i read a thread actually from another forum, they created feature by just using different color of paint. They were just draw few lines but different width, similar like wallpaper but its was not. Their color mixture is absolutely great and impressive, i guess not so pricey and definitely low maintenance.
Just another input for you. Hope you like it.

ya, it is what i said. this picture is nice.
I know wallpaper is the easiest way i guess. but if really can find professional painter, labours fee might be higher but in term of maintenance i think this is the better way.