If you look around, you can see some parses from raids. They tend to be pretty varied right now, but it is fairly safe to assume that Holy Radiance will be around 20-40 % of our healing on AoE fights. It is also fairly safe to assume that protector of the innocent will be at least 20% as well. The contribution from our normal heals will be only around 20% as well, with beacon and others filling the rest.
As per the OP, holy radiance gains 10% efficiency per 10% haste. 10% haste is about 7.14% crit. If holy radiance is 30% of your healing, 10% haste would be a 3% increase in efficiency from just Holy Radiance. The crit on the other hand would increase your total efficiency of all spells by about 3.57%. Then consider that haste would give a 10% gain to HPS for all spells, while crit would give 3.57%. Then consider the Protector of the innocent implications. 10 man will see less powerful Holy Radiance, so it is not always so clear.
The only thing going against Haste is that GoAK only lasts for 5 heals.
Here's a log from our Magmaw 25 kill this week to back this up:
World of Logs - Real Time Raid Analysis
After poking around on there, I feel fairly comfortable saying that mastery is certainly a much weaker stat than haste in most of the common raiding situations. So far, Mastery is near-useless compared to haste on Magmaw, Chimaeron, Omnitron, Halfus, and Valion/Therona. If I were to prioritize mastery, I would be sacrificing around 6% haste for roughly 2,000 HP shields on Divine Light targets. I can't see any evidence that the beacon target is also affected by a shield, so it really does seem like almost a waste, since most of my shields will be significantly smaller.
In addition, I was able to comfortable CS 17 times that fight and still end up on top of the charts (this is post-nerf). Crusader strike is an extremely cheap, reliable way to generate HP and potentially regain mana as well. In my experience, a majority of the fights so far tend to be periods of high damage or "emergency" healing, with long phases of light healing to encourage regeneration. This may change in heroics, but I see no reason not to take advantage of those phases with a few CS hits.
Compare it to beacon-swapping, and it's significantly more mana-efficient with the same (better, because you can still heal a non-beacon target with HL and take advantage of beacon) results.
Played properly, we're still by far the most mana-efficient healing class in the game, and we need to be taking advantage of that.