Finisher scales terribly with gear, since none of them include weapon damage.
That being said, If I recall correctly, Eviscerate/Envenom only receive 15% of your atk, while Rupture (and garrote) receive 22%.
Rupture also totally ignore armor.
And heck, since you're 31/30 - you've got Serrated Blade, so 30% more to Rupture.
End result, your rupture hurts for a lot more then Eviscerate.
Also with Arena promoting survability and healing, burst damage just isn't as important as it used to be.
Edited, Nov 25th 2007 2:31am by Tyrandor