PTS 4.3.0 reduced the effectiveness of enchantments applied to one handed weapons by 50%. This was in attempt to remedy the advantage of getting an extra enchant when using dual wield.

This solution does bring the enchantment's damage numbers more inline with other weapon choices. However, dual wield does still overperform in that it still has the ability to deal damage with 2 different damage types (flame and poison for example) which gives it double the chance to proc a status effect with enchantments.

So my first point is that the attempted goal of this change was not even fully met. Dual wield enchantments still outperform other weapon enchantments in this manner.

Secondly there is also the problem of tanks not being able to apply their strong crusher enchant using one hand and shield with this change, so tanking builds that use a shield on both bars simply aren't viable anymore for most PvE groups. So tanks got indirectly nerfed by this nerf to dual wield.

My third and biggest concern about the change relates to build diversity and play style diversity.

This change greatly limits the optimal placements of enchantments on weapons, and as a result, old play styles that made use of these (now) suboptimal enchantment placements are much less viable.

Here is an example of what I mean by this.

My PvP build stacks weapon damage to increase both my damage and my healing. I want to use dual wield as one of my weapon choices because it's bleed scales well off of a weapon damage spec like mine. I would like to be able to proc my non-infused berserker glyph on my duel wield bar so that I can proc it every 10 seconds when I refresh my (9 second) bleed on an enemy, and then barswap back to my defensive bar for the remaining time until I need to refresh it again. If I do this, I can cast vigor once at the start of my bleed, and another time right as my berserker enchant is about to expire. This way I maintain high healing throughout the fight and high bleed damage, while being able to either burst my enemy or defend myself on my secondary bar. The optimal placement for the berserker enchant for this play style is on the dual wield bar so that the enchantment and ability timings synergize well together.

With the changes to enchantments, the value of berserker is cut in half, and so this synergy becomes only half as effective if used as described above.

If a player using this type of build/style wants to optimize their damage and healing using a berserker enchant post-4.3.0, they are forced to not use a berserker enchant on their dual wield bar (neither can they put it on a snb bar). Putting the berserker enchant on a different bar breaks the fact that we are using a light attack + rending slashes to simultaneously refresh the bleed and berserker buffs, in a single global cooldown. Now in post-4.3.0, it takes us more than 1 global cooldown to perform this same technique, and there is a chance that our bleed is dodged, which could mean that we have to wait another 10 seconds for the berserker enchant to be ready again to try to apply good DoT or burst damage again, so a lot of time can get wasted there too.

So my point with this example is that the number of viable builds and play styles are now even more limited then they used to be with this change, which sucks.

Here's my solution:
1 enchantment per bar.
An easy way to implement this would be to keep enchantments at the old pre-4.3.0 values, but for dual wield, only the right hand's weapon enchantment actually procs. The left hand enchantment is ignored. For simplicity, the devs could just supress weapon enchantments for any weapon in the left hand's gear slot. All 3 of my concerns would be resolved with this solution. Please let me know if you believe this solution would introduce any further problems.