I want to run Subsequence because it will proc Converge and Ruin (edit: and Sweet Release too) each time it gets to a new target, which is pretty awesome (at least in theory, we will see once I hit endgame what that really works out as).
I personally think people hugely over value Cooldown Rate as a stat in this game. The real way to measure its effect is in terms of % increase in action skill uptime. Allow me to explain what that means: Action Skills typically have a duration, that is, how long they do their thing, once that is done, then then have a cooldown time before they are ready again. The sum of those two numbers is the cycle time (how long from activation until you can use it again). If you take duration and divide it by cycle time, you get the percentage (as a decimal) of the cycle time in which the action skill is active and having its effects, for most action skills before including character skills that affect them; the uptime is typically roughly 1/3 (e.g. Sal’s Gunzerking has 20 second duration by 42 second cooldown, hence it is active for 20 out of the 62 seconds of it’s cycle time; ~32.2% uptime). Cooldown rate decreases the cooldown time, but in a manner that has diminishing returns, a 100% increase in cooldown rate will half the cooldown, a 200% increase would cut it to 1/3 as long, etc. the formula is:
cooldown*(1/(1+CDR)) where CDR is cooldown rate buffs (% as decimal).
For the Sal example the skill I’m Ready Already at 5/5 gives +25% CDR, so we have:
How does that affect uptime %? Well the new cycle is 20+33.6=53.6 seconds, and we have a new uptime % of 37.3%, which is an increase of ~5% to uptime, or, from a proportional perspective, it increased uptime by about 15.7%…for 5 skill points we get 15.7% more gunzerking time (assuming constant use when available)? Not very impressive now is it?