Is there a point to having a res if it won't be the highest point in the system? If the radiator was on top of the case and the res were to be a few inches below it, would that lead to air bubbles being trapped in the rad?
Rad mounted on the top. - If the system is turned off the air inside the T will not go through the loop because it is above the tubes that run from each side. However air that is in the pump/cpu block/gpu block will all rise. It will rise if it is physically in the loop and it isn't bled yet. A reservoir should act similiarly and not put air in the line if the barbs are below the airline. if the air is trapped in the res it will not go up in the loop. If it did floppy reservoirs would be pointless
I have a res laying around. I'm trying out the T section and I like it. Took a bit longer to fill and bleed but it has been a champ.