Originally Posted by
shadowboy
The only time you do an undersized finisher to bring something off cd is if the boss is at 2-3% (or 2-3% from some immune phse) and you need the cooldowns NOW (or else lose that one usage of them). Or an add is dying and you have 3 cp, etc. It's never worth it to consider restless blades. You can either pool cp or energy to work around that by planning ahead.
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It sounds to me like you're over-valuing deep insight. Ignoring trinket procs, a 5-point finisher at no insight will do more damage than a 3-point finisher in deep insight. In this case you hit killing spree and start pooling combo points through no insight (using a finisher in no insight if need be).
For example, my rogue has about 87k attack power raid buffed. Assuming wowhead's eviscerate damage formulas are correct, a 5-point eviscerate in blank with no procs is equivalent to a 3 point eviscerate in deep insight with a proc for 7.9k agility. And that's ignoring the fact that the 3-point eviscerate has a 40% chance to not grant a combo point, and a 40% chance to not grant 25 energy.