In hots they are entirely knocked out of stealth for several seconds. So for the revealing part hots is better. If a hero is realy this depending on his stealth, he would get an ability to counter that, or a reduced restealth cooldown.
And about general stealth, i think that at range granting full invisibility isnt a bad idea at all. And to me the ideal range to remove stealth would be based around the hero. For nova for example granting it further away than zeratul.