There's one of those giant rocks at the first point of Goopy Gully that is super tall and I can't even get a drone up there, but back when you could get matches without bots in BfN, there was this guy who always played Deadbeard and somehow got up there, making him a major pain to deal with as a plant. I really hate glitch exploiters and hackers like that.
That aside, I would say that GW2 gets the height system the best of the 3. Not perfect of course, but one complaint you will see even today in GW is how Peashooters and Foot Soldiers on the rooftops dominate the matches, whereas while they are the easiest to get up there, other classes have more options and the maps have more ways to get up there, which is why I feel GW has the best overall moods for their maps, but GW2 has the most fun maps to battle on of the 3 games (barring Time Park anyway).
Vertalicality can really make a map shine, and BfN's general lack of both height and width do harm the multiplayer experience to a high degree. With little high ground and not enough flanking spots, the maps feel almost claustrophobic at times.