Looks like a tie. Though Phillips might last slightly longer, they also cost 1.5k to 2k extra. And I just went through the comparison on your website - performance wise looks like MI is doing a great job. I'll check again with you in early December when I'm about to place the order!On average, 19-20 hours a day. Mi filter costs around 2.6k and Philip's HEPA filter costs 2.4k while the carbon one fluctuates between 1.3-2k.