That is not better than Breath of Heaven's 6202-7442 on a 15 second cooldown for 25 spirit.
That is not better than Serenity's Rune Peaceful Repose's 6202-7752 on a 20 second cooldown for 10 spirit.
The issue with those is that they HAVE A COOLDOWN. Mantra spam is great because they don't have a cooldown, thus they fill in the gaps where you die. With the Transcendence passive they actually heal for a decent amount.