The loop really does help keep the temps down with higher ambient temps. I use one to keep my CPU OC in the summer on air I never could do that. I live in Georgia so 30-40C in the summer. My A/C sucks so my room stays within 30-36C during the day.
If you just have a 1080p monitor right now you may want to do the loop and then add another 780Ti in the future when you need it.