From the Rift forums, some rogues have been doing some good investigations on the new crit cap and I want to summarize the situation here. According to Trion, the "soft" crit cap is 45% crit. This includes any stat increase buffs, but not any % increase buffs/talents.
What this means is that anything that increases your stats (Fanfare of Power, Powersurge Vial, Vitality of Stone, Ambidextrous, etc.) pushes you toward the soft crit cap of 45%.
Anything that increases your crit percentage by a fixed amount (Ruthlessness, Eagle Eye, Motif of Focus, etc) does not count toward the crit cap.
This means that the soft crit cap is actually a crit rating cap. The crit rating to reach the cap is currently 1187 crit. This is easily reachable in Raid gear if you're using a crit sourcestone and if you are heading into HK, its a virtual certainty you'll be reaching it.
What happens after the crit cap? Normally, its 26 crit rating for 1% crit. After the crit soft cap is reached, its 132 crit rating for 1% crit. That is a 5x increase in rating to get the same 1% crit. This means you want to avoid at all costs going over the crit soft cap.
The best way to avoid this is to swap out all your crit essences for AP essences. Here are the top 7 AP essences that every rogue should be using once they start approaching 1100 crit rating fully raid buffed (and where to get them):
- Flowing River - 20 Inscribed Sourcestones (Mercurial Savants)
- Woodland Hunt - 20 Inscribed Sourcestones (Students of the Vale)
- Rushing River - 20 Inscribed Sourcestones (Mercurial Savants)
- Grave Rites - 20 Inscribed Sourcestones (Grim Disciples)
- Necrotic Rites - 20 Inscribed Sourcestones (Grim Disciples)
- Shade Slice - Drop from Death Raid Rift
- Final Cut - Drop from Death Raid Rift
As you can see, your main goal should be to amass Inscribed Sourcestones, and if you run any extra rifts, they should be death, for a chance at Shade Slice or Final Cut. Good hunting!