At the moment tankadin with Battle Healer (assuming normal fight with tank swapping) and a holy priest in dps chakra (with PW:S, as it is a smarter heal than flash procs) do more or less the same amount of dps and healing.
And at the same time a disc priest does twice that on every account with Atonement.
There are only two ways to beat disc:
1) heavily aoe fight without much moving and no need for healing (Mind Sear ftw)
2) really fucking heavy aoe damage fight, where your PoHs don't even overheal (really, disc priests usually don't overheal. If you don't overheal either and go on a maximal rotation, you can't help but win in hps)
Leaving this aside, what about the talents?
Last row (DS/Cascade/Halo) is obviously situational. It's only smart to change it before every battle. But... that's not all. 75 and 60 rows should be changed too. Okay, you can leave 75 untouched if you are not awfully familiar with the fights, but 60... lessee.
PW:Solace is a nice filler spell, but... you just don't have the time to use it if the raid's in heavy damage phase. In 25 mans it's more or less okay, as the other 5 healers will just have to fill for you, and it helps if you are not comfortable with your spirit yet, but... goddamn. This is not the holy spec I used to love. Holy was all about having tons of different healing spells, and not being able to pull even decent-for-the-previous-expansion dps. In other words, you sit on the sidelines, follow tactics, and know in your blood when you should pop the hymns.
Mindbender is kind of strange too. I am not used to getting a Shadowfiend out without a Hymn, and now they want me to cast it every minute? But, I guess, best option for heavy aoe battles.
The free flashes is a good old friend, of whom we have no need --unless we are in direct healing chakra.
So? Raid finder >> PW:S definitely. I really really fucking hate how they forced us to use Evangelism though. I've been avoiding it for two expansions already, and I was doing really well, thank you very much.
What I would have been okay with? Give us atonement-related shits only in dps chakra. Actually make the dps chakra just atonement-style healing, it buffing up PW:Solace besides everything else. Or just add an atonement chakra. Sheesh. That would give us an excuse not to use it while in the other chakras.