I have finalized the below 2 models: Ispring ($565) vs Waterdrop ($799 after coupon). Have a question about your comment on Filtration. Ispring says 3 stage filtration and Waterdrop says 9 stage filtration. Obviously their definition of filtration is different lol. Can you please advise on how you determined that Ispring is better? Thanks a lot

1. https://www.amazon.com/iSpring-RO500AK-Filtration-Remineralization-Monitoring-dp-B09CHBC9CP/dp/B09CHBC9CP/ref=dp_ob_title_def?th=1
2. https://www.amazon.com/Waterdrop-Reverse-Osmosis-Filtration-Tankless-dp-B0987FCQQW/dp/B0987FCQQW/ref=dp_ob_title_hi