Id love them, but I dont think that they should be 'static' if you know what I mean.
I think that a number of tier 2 chests should have a random chance to turn into tier 3's.
This is because it would be unfair on the guys who didn't get the best gear from their routes, so they have no chance to fight over said tier 3.
In short, the guy who gets the iron armour and diamond sword will become even more powerful, and other players will have an even harder time taking him out.
EDIT: I also noticed that this would change people's perspectives on chest routes, but in a good way.
Rather than a mad rush for the tier 3's, you would get concentrated fighting on chest routes with high numbers of tier 2's, but this would be spread over multiple chest routes, rather than just one.
Another Edit
: I just thought I'd give my views on what the contents of the chests should be in my opinion. A high spawn rate for high level armour such as Iron and perhaps even diamond boots or helmets, Not diamond chestpieces or Leggings because they would make the wearer nearly invincible. Bottles of Enchanting would be great, perhaps a stack of five, or at least enough for one level, so that the user can enchant their chosen item (if they know the locations of enchantment tables :3) I don't think that weapons should be added as getting a diamond sword from a chest is just a bit too easy, there should be a risk in exposing yourself while you craft the item, because of how powerful it is. On that point, Iron swords could be a possibility as they aren't overly powerful.
I also believe that certain potions should NOT be added, such as poison or high level instant damage, Their effects are just too powerful to be fair. A poison potion is one of the most devastating weapons in the game as the effect often lasts long enough to bring you down to a few hearts, making it an almost certain death for the victim. Instant damage is just a bit too cheap in my opinion, just tossing a grenade at someones feet to almost half their health, then running up to them, whacking them a few times and killing them just seems too unbalanced. Oh and of course, invisibility. Just NO. Yes it is hilarious to watch a terrified player swing around wildly while they get hit from an unseen enemy, but if you put yourself in the shoes of the victim, there is nearly noting you can do to combat them, save for just swinging wildly