>>18226139I should've said BB healing system in general because being able to heal back any damage you take by being agressive helps a lot. Vials also have a pretty decent chance to drop from most enemies and are plentiful so you rarely need to stop and for them.
Estus flaks are always regenerate automatically so you never have to worry about them, which is a positive but also a negative since you can play more carelessly, which makes DS2 system a touch above the rest in my opinion since flask are extremely slow to drink so you have be more thoughtful with them and gems are a compliment to them since they're fast to use but will heal you slowly, which makes it more intesting in my opinion.