The thing you have to realize is that a Wooden Club and a Steel mace are effectively the same classification of weapon. In other words, the Steel Mace is going to be better, in general, than the Wooden Club, as it is a 1 handed bludgeoning weapon made from better materials....but that's it. Your not looking at massive divergent weapons/armor in the game. There are no 'Mace of Disruption' boss drops to throw things really off kilter.
Just as was said previously, certain equipment is better vs certain mobs, certain equipment is a little bit better because its made of sturdier materials, and some equipment, made from more exotic materials, might even include a Free equivalent enchantment on it, but it is generally only effectively a Tier 1 enchantment, so not massively game-changing.
Each Weapon and Piece of armor has several factors that go into how effective they are, but in and of themselves, none of these factors drastically make a weapon stand out in all situations.
They each have a limited number of enchantments they can hold, with the Torso Armor piece holding the most so far in game, at I believe it was 7 spots. Each enchantment you put on the gear costs 1 spot per tier of the enchantment, so at most, that body armor could hold 2 Tier 3 enchantments, and 1 Tier 1 enchantment, plus if made of an exotic material, have 1 additional Tier 1 equivalent enchantment on it. This is not as huge a difference as gear has in most other MMOs, where the right piece of gear can get you through entire quest lines nearly unscathed or unstoppable (Armor or Weapon)
Also, every piece of gear has a degredation rate, as you use it, it breaks down. Right now, there are no plans for a Repair ability, so gear must be periodically replaced, and the reagents and exotic materials can be harder to acquire than going with the simpler version of gear, not to mention more time consuming to craft overall.
Finally, there is no Level requirement to use specific gear, and not really any Stat requirements worth mentioning. This means a Brand new, day 1 character can join in on a Raid with his friends who've been playing for 6 months, and all the friends have to do to make him comparable in battle is to throw him some mid-to-high level gear. The main deficit that the newb will have in the battles is a lack of combat options, as they will only have unlocked the starting skills for their archetype in this scenario, and they will not have increased their Talent Tree abilities at all yet. Both of these things are nice, but neither by themselves is gamebreakingly going to set a character above the others in a Raid Group.