This skill leads is imbalanced, proof as follows:
Duncan HM: http://i.imgur.com/usfAK.jpg
There's absolutely no way a team of 8 players not using Shadow Form can kill their way to Duncan and finish him off in 3 minutes, even with consumables backup. I know from experience that killing Duncan with 7 heroes + 1 player, no cons, takes about 25 minutes. This is 8 times slower than using Shadow Form, despite also having 8 times the firepower.
Ooze Pit HM: http://img442.imageshack.us/img442/3958/gw047.jpg
Again there's no way a team of 8 players not using Shadow Form can kill their way to the Prismatic Oozes and finish them off in 5 minutes. I know from experience that the fastest H/H times possible with Elementalist primary (no cons) are about 18 minutes, and the fastest H/H times overall are about 15 minutes. Again this is way slower than using Shadow Form, despite having 8 times the firepower.
Kathandrax HM: http://i55.tinypic.com/svpbvq.jpg, http://i53.tinypic.com/2i1c6.jpg
11 minutes Kathandrax HM, done alone, with par times for H/H no cons at about 40 minutes.
I don't intend to talk about the Underworld or Fissure of Woe or Domain of Anguish here. I'll just point out that speeds this fast in other areas of the game are retarded, and Shadow Form is the key skill to such times.
A few more things here.
Why is Shadow Form so fast? - it allows the player to run past mobs. Running past mobs is significantly faster than killing them.
Not everyone can achieve times that fast - not everyone can clear Ooze Pit in 15 minutes H/H either.
PuGs still fail despite being "invulnerable" / SF takes skill to use, hence SF is not overpowered - balance should not be based around bad players, or we'll be forced to argue that interrupts are bad because bad players can never land them. What is important is that these times are achievable. Besides, PuGs still failed with pre-nerf SF, so that isn't overpowered either ... ?
Consumables have a greater effect than SF - perhaps, but I'd challenge anyone who says this to post a screenshot not using SF / Vow of Silence / Obsidian Flesh / related skills but using consumables, to clear these areas solo. Post a screenshot with /age. See what times they get. I doubt they'll ever get to the end.
If you don't like SF don't use it, don't ruin the game for people that do use it - in that case, I suggest ANet introduce the skill BAMPH for players. Whoever doesn't like the skill can simply not use it.
Nerf to SF will kill the economy - SF has been nerfed before, and buffed before. I don't think the economy has ever died, however, even when SF was not viable. Impacted, yes. Died, no.
Nerf to SF will make people cry that they can't buy Obsidian Armour or BDSes or similar anymore - I've yet to see any non-SF users say that they think SF should stay the way it is because without SF, they can't buy Obsidian Armour or BDSes or similar anymore.
What about Obsidian Flesh and Vow of Silence? - maintainable spell immunity is bad, but neither are as pressing as Shadow Form.
Proposed solution: change Shadow Form (PvE) to Shadow Form (PvP).
J

