For 25-mans haste is pretty awful in comparison to mastery, EoL is usually your top healing spell and going for that high haste on a 25-man as holy is just asking to be gimped on purpose definitely not recommended. For 10-man though 13k haste is workable since you can raid heal with renew much easier while camping on serenity and refreshing with cascade.
13k is a 10man build that is pretty boss if you are above 530 IL. Not great in 25man since you can't get enough renews out. The only fight were I would rock 13k in 25 man would be dark anne heroic due to the fact PoH hits 1-2 targets, everyone is so spread about all you can do is single target heal.