The choice between reverse osmosis water vs distilled is really a choice between a fixture and an appliance. Reverse osmosis is plumbed under the sink, fills a small storage tank on its own and gives you a dedicated faucet you can turn on at any time. A distiller sits on the counter, makes one batch, then stops until you empty it and start it again. That difference decides most kitchens before purity ever enters the argument.
How each one is produced
Reverse osmosis pushes household water against a semipermeable membrane. Water passes; most dissolved salts and many dissolved contaminants do not, and are carried away down a drain line. Distillation does the opposite trick with heat: it boils the water, leaves the dissolved solids behind in the chamber, and condenses the steam back into liquid. One separates by pressure and membrane, the other by phase change.
Volume is what decides most kitchens
An under-sink reverse osmosis unit refills its tank in the background, so drinking water, cooking water and the ice maker all draw from the same supply without anyone thinking about it. A distiller produces a jug at a time over several hours. If the household only wants water for a CPAP machine or a steam iron, that is plenty. If four people want cold water on demand, batch production becomes a chore quickly.
Running costs and upkeep, in kind not in dollars
Reverse osmosis costs you cartridge changes on a schedule, a membrane every few years, and some water sent to drain for every gallon produced. Distillation costs you electricity for every batch, plus descaling the boiling chamber, plus replacing a carbon post-filter if the unit has one. Neither is maintenance free, and both fail quietly rather than loudly when the household stops doing the work.
Which one suits your house
Pick reverse osmosis if you want the whole household drinking off one tap without planning ahead, and you have space under the sink plus a drain connection. Pick a distiller if you rent, cannot modify plumbing, need small volumes of very low mineral water, or want a device you can move. Neither one addresses scale on your fixtures and water heater, which is a softener question, not a drinking water one.
Questions people ask about reverse osmosis water vs distilled
Do I need both a distiller and a reverse osmosis system?
Almost never. They solve the same problem by different means, and running both duplicates cost and maintenance for a result you will not taste.
Can a distiller be plumbed in like reverse osmosis?
Some larger distillers can feed an automatic fill and a storage tank, but the standard countertop unit is a fill-and-run appliance with no plumbing connection.
Which one is easier to install?
The distiller, because installation means finding an outlet. Reverse osmosis needs a cold water tap, a drain saddle or connection, and a hole for the dedicated faucet.