Set up: 15 mins to remove packaging, check instructions & remote control, put filters in and start it. Filtered air particulate matter (2.5ug and 10ug) in 5x5 m2 room in 20 mins from ~74ug to 25ug.
Extremely easy to use and operate.
Not noisy at highest fan speed(10), and low fan speeds are very quiet.
Optional Fan function gives nice light breeze even at 5m distance.
Filters @$99 per set. (2 sets required) are pricy, but last 1 year if operating 12 hrs/day. Unlikely to use that often!
Only improvements could be:
1. a little trolley or built in wheels to enable easy moving between rooms.
2. Handles for carrying. (Not supposed to use the loop).
Summary: Does the job. Very impressed.

I am asthmatic and very sensitive to smoke. I had a severe asthma event due to smoke from bushfires in Tasmania earlier this year. I purchased the Dyson in late January and it has been performing beautifully since then. Once the bushfire smoke cleared and I began to recover the cold weather hit and neighbours began using their wood fires. There have been many nights when I am sure I would have been calling an ambulance if I did not have the Dyson. It is fantastic. I researched other products but the proven effectiveness of the Dyson combined with a lower price tag convinced me.

I use to get really bad sinus blockages when waking up, but since getting the Dyson Pure Cool tower I don't have this issue anymore.
I did had to get the fan replaced under warranty after 1 month of usage due to a really high pitched sequel but Dyson customer service has been great to deal with and they organized shipping for it to be sent back for repair and they replaced it with another one. Very please with their service and haven't had an issue with the replacement fan since.

I love the look and the idea of this fan, but in reality it doesn't really do much more than a $50 fan, especially for the high price tag of $799.
Fan wise, it's weaker then a cheapo tradition fan.
Think more of how an air conditioner blows air, but without the cooling.
Weak air flow, not enough to help during hot summer days.
Noise wise, it's only quite at low levels (1-6). 7-10 is pretty loud.
I don't have any allergies, so probably not benefiting from the air purifying function.
It does look super cool and modern though, a great look for any contemporary home.
The mediocre review is probably more of a reflection of my poor money management.