The first situation is on turn 8. The set-up: your opponent just wiped the board and you lost 3 1/1 Soldier tokens (it's not a good day for you), you have 10 mana untapped (nothing played on the last turn), and nothing in your hand. With Proper Burial, you gain a whopping 3 life. With this card, you can pump your mana into this and gain 10 life, a 300% increase!
The second situation is the same as the first except you lost 16 2/2 Cat tokens and a 6/6 Kemba, Kha Regent with no mana available. With this card, you gain nothing, but with Proper Burial you would gain 38 life.
In certain situations, this card is better than Proper Burial, but it is NOT strictly better nor is it strictly worse. It all depends on your deck build. If you have a white token deck, get Proper Burial. If you're running a white-green ramp deck with a few biggies, get this card. Basically, if you're going to have the mana to spend, this card is good.
Pros: Trades spare mana for life, can make token deaths worthwhile
Cons: May not have mana to spend, bad in board-wipe scenarios