Pros: It requires no extra equipment or investment.
Cons: It’s expensive (relatively). You don’t have control and rely on consistency when inconsistency is pretty much guaranteed. Lots of plastic waste. No matter what you do you’re not going to stop scaling in the service boiler without a lot of water waste.
Pros: Absolute control and consistency.
Cons: Takes time. Not the most cost effective method. Requires extra equipment.
PRos: On demand. Most convenient. Good at removing most things from water. Can run with remineralisation in line so no faffing around adding things.
Cons: Less consistency than distilled, varies based on the water put through it. The filters need replacing periodically so there is an ongoing cost. Large (comparatively) upfront cost. Needs counter space or undersink space.
Pros: It’s…on tap.
Cons: Variable quality. Will have stuff in it you don’t want in your machine or your drinks e.g nitrate, chlorine etc, some of it can be removed with filters but not all.
Zero water jug:
Pros: Low up-front cost. Highly effective filters. Can be mixed with tap water to bring alkalinity and hardness.
No option is perfect.