Diablo – Anniversary XP bonus boost

As of patch 2.0.5. The hard cap for gold find was removed.

The 300% Gold Find cap applied to items and Paragon Points has been removed

First thing first: Gear drop level (understand quality) is tied to your character's level (1-70); you can loot the same quality legendaries/gear when you are level 70 in Normal difficulty or Torment 6.

Then the answer is no, but the phenomenon you are witnessing can be easily explained:

A well geared character has pieces of equipment that synergize well together (crit damage, crit chance, Intelligence in your case, attack speed, etc.) for an overall good DPS. Since your Wizard is well geared any piece of equipment you add will synergize with the others. Let's take a quick example:

• If your gear brings you a lots of crit damage already, a new piece of equipment that brings some crit chance will fit well with your overall gear.

This explains why when you loot something for your wizard, since your gear is good you might not have a DPS upgrade. However, the loot still syngerizes with the rest of the gear and so the DPS drop is not that much.

On the other hand your Demon Hunter doesn't appear well geared meaning that the chance of a new loot synergizing and thus increasing your DPS is very low. And a loot that lowers your DPS will appear worse on your DH since the rest of your DH's gear can't make up for its worse stats.