Reverse ATX cooling difference? (blocks hanging on bottom of GPU, air in loop??)

[Tolem]

I saw in another thread someone said to mount radiators with the barbs oriented UP so that air doesnt get induced into the radiator / loop.

It made me wonder are there any downsides of a reverse ATX design when liquid cooling? Considering the blocks will be hanging off the bottom of the GPU instead of sitting upright on top, and the connecting piece that connects all the cards together would be mounted upside down as well (I know my sli bridge is upside down, not sure how the blocks that connect sli cards for liquid are designed).

Thanks for any tips!

[aerial]

It used to make difference for air cooling and some heatpipe coolers, there were not designed to work optimally in upside down position (vs atx).
For water cooling main difference is aesthetics, if you want case on your left and want window, inverted atx is the way to go. On a small desk, there is usually more space for case on the left side (since right is taken by mouse/mousepad).
Afaik it has no impact on performance of water cooling loop.