So here's my problem with the flex. It basically turns into the problem I have with every other standard layout case in that there's really no good way to do direct airflow.
By this I mean the following, by putting the GPU at the bottom, the only way to prevent having the air redirect 90° is by putting a radiator at the front, and that's difficult to get right and not grossly increase case size.
Putting the GPU at the bottom inside the slot itself and the radiator by the motherboard:
Dear lord is this awful for airflow. Not only are you choking the fans on both sides, but your exit strategies are awful. You direct air into the Motherboard, which acts like a splash plate to reduce velocity (increases pressure). At which point the now redirected air has to flow to the outlets, to be choked once again, again reducing velocity and increasing pressure. This also has the issue is creating stagnation eddies that cannot effectively dissipate heat, particularly in areas with right angles, like behind the graphics card. Additionally, without extreme amounts of porting, your graphics card is going to be doing the same thing, which is already bad enough in the Node 202. Replace the side panel with a solid plate, and I assume the front and back (reverse side glass, not rear where IO is) will be solid as well, and you're begging for the air to stew. The problem is bad enough in my Node 202 and that has a very open front and a decent amount of side porting for exhaust.
This is why I loved the original design so much. Extremely practical without any frills. Everything had a purpose and it was nearly perfect. Nothing was cut I couldn't live without. It was wider than my 202, but I was fine with that as it was overall more convenient to transport, which helps when you move often and take it everywhere to do VR demos.
Sure, you have the GPU facing the glass, but the amount of air that circulates through the case should mostly mitigate any problem that was caused.
At this point I've been designing my own case for the past little while while I've been waiting to see where the C4 goes as it seems more and more likely that I'll be building my own that expand on what I liked about the original design.
Much love.