Which is better, Insightful Reflexes or Extend? Am asking so because I am considering swapping one of these for a Greater Spell Focus feat.
Currently I am in favor of swapping out Extend - it's been heavily nerfed post-U9, now that it no longer works on lingering spells but only on buffs. For a normal Lv20 caster, that would be 20 min. of buffs without Extend, 40 min. with it. But let's be frank - unless you are doing some extreme challenges like soloing an endgame elite/epic, chances are you'll either reach the next shrine or be dead within the next 20 minutes. Plus that if you've already got some endgame SP regen gear like the Bauble, the importance of Extend can be mitigated.
Insightful Reflexes - while some people believe that it's not as good as those more spell-oriented feats, I think this one does have its own virtue, and may well have helped me escape several of those a-lousy-dead-wiz embarrassing scenarios already.
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On a side note - I was never a big fan of Quicken, and unless I know beforehand that I am going to enter some CC-heavy epic contents, I generally won't turn my Quicken on. But this is gonna change soon with the metamagic toggle that's going to arrive with U11. Now I can toggle Quicken on for CC and cloud spells, while keeping it away from wasting my SP elsewhere. This is going to make Quicken more useful and popular.