Originally Posted by
valtari
Haste scaling should be linear in that regard, as such there shouldn't be any actual breakpoints, even if your tooltip might not reflect that.
One point that might be of interest is getting Cobra Shot just below 1,5s. Meaning a pair would always take just about 3 seconds, which for most scenarios should be 'optimal' in the sense that it allows for clean/tight multi - cobra - cobra - multi or KC - 2x instant, 2x cobra - KC.
In practice though, getting Cobra to that point without any Haste cds won't really be possible with current gear. More often than not, you'll have either Bloodlust, Focus Fire or Dragonspine Trophy up anyway, where with any of those you're already easily below 1,5s even without specifically stacking Haste on gear.