There's a lot more diversity and challenge in D3 GR. They are not comparable at all.
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It's by far the best way to get an Arcano Crystal. The trinket has an insanely high value for a lot of DPS specs, to the point where even an 860 one beats any other alternative (MM Hunters for example). Getting a 910 (or higher) one is a massive increase in all scenarios. If you're at least somewhat serious about your character, you'll farm that Arcano.