Hmm, yeah the amount it heals for is a bit unclear atm, the talent builder tool states the following:
1pt out of 3 in Efflorescence = 10% of amount swiftmend heals for over 7 secs
2pt out of 3 in Efflorescence = 80% of amount swiftmend heals for over 7 secs
3pt out of 3 in Efflorescence = 120% of amount swiftmend heals for over 7 secs
So at least it would be healing for more than the regrowth based version (assuming this is correct)