Airmega 350

Housefresh.com's reviews are useful, because they measure sound and CADR using a consistent methodology, allowing you to compare among units. They've tested the three you mention. I'd suggest making a table of CADR and noise at each fan speed from their reviews. That's what I did. Based on a quick l

There is the Coway 350 with its pelleted carbon that might be worth checking out if you want to stick with Coway.

Good brands with affordable units are Winix, Levoit, Coway, Alen, and many more. A Levoit Core 600 for instance is around 280 dollars and does 350 range CFM...almost double the Dyson for 1/4th the cost. Winix + Coway have great units too. (Coway used a fungicide/pesticide on the filters for antibact

Levoit will still clean your air. They even publish PM2.5 CADRs for most of their models. While the Levoit Vital series and EverestAir perform very well, they may not have the build quality of the more premium Coway units. Is it better to slightly oversize units so they’re effective on medium/quiet

You can't go wrong. I just bought 3 replacement filters from them. 2 for my Winix 5500-2 and my Coway Airmega 350. They fit like a glove and work great.

I'd go for the Coway Airmega 300. That has square prefilters. But the 350 and 450 will probably be great too. The difference with square vs round prefilters is that the round prefilters you vacuum, while the square prefilters you can rinse in the shower.