I have enjoyed chakra in holy alot. It is very versatile, and I enjoy versatility and adaptability in a healing spec.
Disc is a little more of a one trick pony. It still has large tool box of heals, priests in general have that, but alot of the throughput of disc comes via shields. It is really good, but the healing style dosen't really change all that much. I am not convinced that a smite/archangel spec will be as viable as a standard disc healing spec in a raiding environment, but it will be fun in 5 man or farm status raid content. We'll see though.
I like the dynamic with heal and weakened soul in the disc tree. When you are in a light healing mode, you can shorten the weakened soul debuff with your efficient heal. Increasing the uptime of your shields. It shapes up to make a really efficient tank healer combined with grace stacks.
It will come down to preference really. I like holy, because of the chakra mechanic, but others may find disc better. And it might be better to min/max by swapping specs depending on the raid encounter.
My two cents