That comment isn't forum post theory crafting, it's from experience playing the actual content.

A tenth of a second isn't going to really affect you in AoEs, especially when many are predictable. If you are eating AoEs by 1/10 of a second difference, there are other things aside from stats that you need to be worrying about. Nothing in this game has that tight of a timing.

Fact remains is that every second you aren't casting, your spell speed is going to waste. The less you spam, the less it matters. With determination, you get the full effect on every cast. It's not fair to directly compare HPS of ss to det expecting yourself to be spamming cures for 60+ seconds straight.

That said, I don't really have a horse in this race. I main SCH, so my clear choice is crit. Even if it weren't, the difference between the tertiary stats is so small that picking one over the other isn't going to impede you from finishing any of the content. My primary point is that the flaws of theory crafting need to be pointed out. It definitely has its place, but it can't always be taken as gospel.