I just went with the best rated I could find and it was top rated in many reviews I read. They are extremely popular in California and in states that have wild fires, where the smoke tends to penetrate houses nearby and is a bear to get rid of. Anything with a H13 filter will help, but the key to the unit I bought is it moves more air thru than any of the others.....by a mile.
The filters are not cheap, over $100 every 6 months or so, which I'll be happy to pay for peace of mind (and to get the wife off my back).
If it works, it stays. If it doesn't, it get returned. Simple as that........