BioGS (SPA-421A/SPA-582A)

Fair. I've been very happy with the sub-200 Rabbit Air BioSpa GS I got used on Ebay, it's held up very nicely.

Seconding Rabbit Air. I have a Minus A2 with a VOC filter package that I need to vacuum weekly as it becomes caked with dog hair. I also have their entry level BioGS that’s now 18 years old and works flawlessly. They have excellent customer service too. I also have a Coway Amega, which works just fine in my little foyer, but it’s not as impressive as the Rabbit minus A2.

RabbitAir BioGS is personal favourite.

Absolutely, very quiet on its lower settings.

See if you can find a RabbitAir unit. Anything designed as a "smoke eater" will also be able to scrub the smell from your room while it's being occupied

Never had a problem, just rotate the filters at the recommended intervals. I think it's about every six months, I know some models say three years with regular use. It's not a smart machine that can integrate with HA, but I swear the BioGS air quality sniffer knows I'm going to fart before I do. I have it set to auto modulate the speed when it detects low air quality so it'll go from a whisper to a jet taking off for a minute as it scrubs the air. Newer ones of their base model run about $300, and the ~$700 wall mounted units are their most serious "I put this in my cigar room" level

Rabbit Air or Lichen Air. They really don’t do that well with dust, they do remove the smaller particles that get past your lungs and get into your bloodstream. We’ve had the Rabbit Air for almost 4 years, no issue, app connectivity, amazing customer service. Lichen Air about two months, two large Hepa 14 filters, no app connectivity, I feel it’s simpler but moves an amazing amount of air, wouldn’t go wrong with either.