Originally Posted by
Hellpyre
As far as the preventing damage schtick, Redemption is hands down better at protecting casters when it's in range, since it obviates the need for a concentration check at all. Unity has a better working range as well as actually reducing the overall damage dealt, but requires more active investment in the form of spell slots to keep bonds up, as well as actions to refresh them when they run out.
It really comes down to this: if you have a tank that isn't using reactions regularly, Unity cleric will give them a good reaction to protect a given squishy. Redemption paladin will itself be a tank for the party, and can move to where it's needed at a given moment in the flow of battle.
Also, Unity hasn't seen a published release yet, so we have will see if it changed some in Tasha's.