I tried the generic filters that were supposed to be the same as the Honeywell filters. They don't fit the Honeywell filter enclosures so you get plenty of air leakage. If you want good filtering, buy the real thing! Go with real Honeywell filters from Atomic Filters, your allergies will thank you.
I ordered the Honeywell filter that was very hard to find. Atomic Filters was able to ship the exact filter I needed. It took a while to deliver, but worth the wait.