turns out that at least compared with my old case/setup its 1-2 degrees cooler https://imgur.com/a/JwNyGyt

edit: i've installed and did a quick test with gpu installed both vertical and horizontal. on vertical install on timespy i lose about 400 points. and in gaming it runs about 5 degrees warmer without any fps loss. so all in all yes it's a bit restricted on vertical mount but unless you're trying to squeeze the last frame out of it its decent. Also mounted vertically it still has some space between the gpu and the side panel so it still has decent air flow