The short version
Both premium $1,000+ air purifiers with different filtration theses. IQAir is clinical HyperHEPA H14. Molekule is PECO + True HEPA H13 + premium smart features.
When IQAir HealthPro Plus is the right pick
If you want clinical-grade HEPA filtration with Swiss pedigree and best long-term ownership economics — IQAir is the right shape. Accept lack of smart features.
When Molekule Air Pro is the right pick
If you want PECO photocatalytic VOC destruction + premium smart-feature integration — Molekule is the right shape. Accept higher long-term filter cost and PECO efficacy debate.