I'm in the camp that height advantage = dice advantage is too much, but equating this to the 9th level Foresight spell is a pretty disingenuous argument and actually weakens the good arguments made here in this thread.
Just having a 8 hour non-concentration advantage to saving throws (far rarer than attack advantage), ability checks (fantastic for shove, grapple, dispel magic and counter spell), and not being able to be surprised is powerful enough for a decently high level spell.
Maintaining a high-ground advantage is also far more difficult than the attack/defense advantage granted by Foresight.
In many cases, enemy movement can simply deny your high-ground advantage by closing the gap to threaten you. A single casting of Misty Step basically guarantees it. If the AI was smart enough, it can even deny you line of sight to render your high ground useless. It's still overtuned and should be changed due to other reasons, and because the AI isn't clever enough to deal with it, but it's not Foresight.
I assume our ultimate goal here is for Larian to actually listen and apply this feedback. I don't think hyperbole is going to help that.
As much as others have defended, I do think that Topgoon has a fair point in that making a direct comparison isn't entirely fair - the spell does do more as well, and just pure adv/dis alone without the saves and ability check features would probably drop its overall spell value by about 2 or 3 spell levels, to 6th/7th. I wasn't intending to make an argument, just putting it forward as a point of contemplation for the discussion.
