Wow... you're bad. The only spell that benefits more from Crit than Haste, even as a relation of percentages rather than ratings, is PW:S. The difference between the two stats is not noticeable in any way. If you look at a raid buffed Disc Priest hanging out at around 40% crit the gain from 1% crit is an average gain of 4 healing. You would need 1,246 crit rating at this point to get a 1% gain on PW:S.
You're talking about numbers which will never, ever make any difference in any fight. If you cast PW:S 300 times in a fight you'd get 1,200 more healing from 1% more crit. Now, that's at least a 5 minute fight, so let's say you also cast Penance 10 times. Seriously PW:S spam here, completely useless Priest. But wait! You cast a spell >1.5 seconds 20 times, hmm. So let's say you have 500 haste. That's a 1.211 second cast. Adding 45.91 haste rating, the same amount of rating needed to get 1% crit. You're not at a 1.196 second cast. That means you saved .15 seconds. So how much would .15 PW:S casts be worth? Even without the crit included: 1,530.
You... freaking... fail. You're trying to pretend that any advantage on PW:S makes crit superior to haste. Fact is... no, crit is horrible even for PW:S spam. You can try to dance around all you want but you don't have a leg to stand on. And that's for PW:S spam and only casting Penance twice a minute. Now compare to actually using Penance frequently, which is much more likely.. Now you're going to be getting an entire extra PW:S cast... you know, instead of less than an eighth of a single cast. :
By the way, the 30% is not 'math', it's a rule of thumb. The 30% people talk about? That's before raid buffs and talents. That means you're actually up well over 40% as Disc. Brilliant on completely misunderstanding what people are saying about haste though, kudos.