The overwhelming number of people writing those reviews are full of crap and many of the complaints are either absurd or not the device's fault, from personal experience i've found those airblades work fantastically.
The only complaint I see there that has any sort of credibility is the poor drainage and water collecting around the area. And even that complaint has holes because #1- It's something that affects all hand dryers (none of which function anywhere close to as well as Dysons) and #2- It's easily prevented by basic bathroom cleaning (or some sort of drain and/or absorbing mat underneath). You're not going to get pools of nasty liquid like many of the reviewers say are occurring without there being inherent problems from the cleaning staff (at least not any company establishments that properly clean their bathrooms throughout the day as they're supposed to). You'd get the same problems with nasty toilets if they weren't cleaned regularly, but you don't see many idiots complaining about toilet brands when the cleaning staff aren't doing their jobs properly (or whoever is in charge of getting things cleaned).
The things work fantastically and get hands incredibly dry. Any review that says they don't work are either full of crap or got a defective one. I've also never been in any danger of banging into the sides (the force is enough to dry your hands but not enough to be a problem with holding them still), and my hands are quite large and I'm usually not good at holding them still. I'm also not sure of many people who use these without washing their hands first anyways (I can't see why anyone would be using these unless their hands were wet from washing them), so what's the big deal about having to slightly brush the sides of the device even if you suck at holding your hands still for a couple of seconds? It's quite common in a lot of public places that you're going to come into contact with a door, or something very shortly after washing your hands that is likely far filthier than that dryer was.
I've never liked hand dryers until these Dyson ones began to pop up all over the place. These are the first time they've ever worked in any proper manner and actually get your hands dry. The old ones suck and the sooner they're replaced by Dyson or similar ones the better.
