As a Disc priest who uses atonement healing, I am very curious as to how much the new buffs to it have helped. However, the PTR will not work for me for god knows what reason so I am trying to find anyone who might have tried it.
Exactly how hard is Holy fire hitting for? How hard is smite hitting for with the Glyph of Smite and 5 evan stacks?
Well, Holy Fire hits for 30% more than Smite currently does, leaves a ticking HoT for about 1/4 to 1/3 of the initial hit, and if you're using the Smite glyph then your subsequent Smites will heal for 20% more while the Holy Fire DoT/HoT/whatever is active (which, if you use HF on cooldown, is 70% of the time).
I'm far too lazy to run the numbers, but Atonement is in damn good shape in 4.1. It's never going to be our go-to spam heal like PoH or PW:S (if you have the mana to support heavy PW:S usage that is), but it will be a much stronger tool for topping off the tanks and melee, whereas right now it's mainly a tool to grant us access to a nice +15% healing cooldown (time it with PI or my troll racial, mmmmm hawtness!).
As far as your spec, I have to disagree with taking Surge of Light over Soul Warding. Being able to cast multiple subsequent PW:S's is extremely valuable in a raid setting, much more so than a free instant FH once in a great while. There are also a lot of tweaks that depend on your healing style and how it fits into your raid (and of course the content you're doing), so yes it can be hard to figure out some of the talent choices.