I am fairly new to the air purifier game but am a veteran smart home owner. 

The first thing I'll say is that my 2 Alen air purifiers look great. I have a T500 in the bedroom and the 45i in our great room. The 45i in particular could easily fit into any modern space, though it is a bit large.

The features on the purifier are great. It runs silently and clears the air.

My only gripe is that we run the 45i on auto. So it's running 24/7 and while I trust it's doing a good job, not really understanding exactly why it kicks into high mode is a bit frustrating.

I have an air monitor sicking fairly close and even with pm2.5 @ 1-2 the Alen sometimes goes up. 

Anyways, we love it so fair and look forward to expanding our footprint if all goes well.