I guess one concern is it leaves very little airflow for CPU VRM. obviously 90% the air flow is gonna go to the side with the mesh panel.
With glass on the GPU side (how the expect most people to build... the whole reason glass panel is stock, people want to show off their GPU), well GPU VRM is cooled by the cooler. Yes glass on an aircooled GPU will be awful, but for a full loop, if you have to have 1 glass panel, I think GPU side would be preferred in terms of getting some airflow over any parts that rely on it.