AO Smith vs AO Smith
Which Water Purifiers should you buy?
AO Smith Z2+ Luxe RO Under-Sink Water Purifier
AO Smith Z9 Pro RO Water Purifier (Ambient & Instant Hot)
Final Verdict: AO Smith Z9 Pro RO Water Purifier (Ambient & Instant Hot)
Why choose AO Smith?
If your kitchen design specifically calls for a hidden purifier — no visible wall unit, just a small tap — the AO Smith Z2+ Luxe is the only under-sink option we found worth featuring. The catch is honesty about proof: only 33 reviews back this up, thin compared to nearly everything else in our lineup, so treat the 4.3★ rating as promising rather than exhaustively tested.
Why choose AO Smith?
If you specifically want instant hot water for tea, coffee, or baby formula alongside RO purification, the AO Smith Z9 Pro is the only genuine option in our lineup — nothing else here dispenses hot water. If you just want the best RO purifier and can boil water separately, the Native M2 Pro or KENT Grand RO get you there for meaningfully less.