Switch in-out placement on GPU blocks.

[Zepticon]

Simple suggestion to have the "IN" port on the GPU on the side facing the front of the case. This is the most likely place for a pump and/or reservoir placement and would be ideal in terms of utilizing the second hole as a drain.
This is how it looks on my build, and with the "in" port in the front i could have mounted the drain in the bottom out port:

 

[Zepticon]

I also came up with two more things:
- On the RGB lights on the plexi GPU blocks, Adding a diffusor and more LED to the light strip would be cool.
- Offer an Acetal/black version if the block (not plexi) (This is a minor thing since you offer the black backplate and that solves the looks.) I also think that Acetal is a more durable material and i would prefer it over brittle plexiglas if offered.