I found this humidifier excellent. It is small - actually tiny - yet powerfull and solid. It doesn't feel cheap and plasticy, is easy and straightforward to operate, comes fully accessorised with universal adaptors - EU, UK, USA - that are incredibly easy to use, a cleaning brush and a fabric pouch.
I have been using it for a month now and I'm still as happy with it as I was on the first day. It conveniently takes regular commercially available water bottles. I usually use a 750 ml bottle - as 0.5 lt would be too small and 1 lt too big - and it lasts me through the whole night at highest setting for approximately 8 hours or so. It is powerful enough to humidify a standard sized bedroom - I have used it up to 35 sq.m. bedroom even though it is advertised as having capacity for smaller rooms. The only setting it has is a wheel to adjust the intensity of humidification - it is not particularly sophisticated and given that this is a travel humidifier, i.e. small, and I generally aim to a 55-60 percent huimidity, I have never really used it to anything lower than nearly highest setting.
There are only two 'nearly cons' for me. One is the blue light that has been mentioned already. It comes from the water tank where the light is located so unless you plan to put some tape in the tank you wouldn't be able to get rid of that light. It is a sedetary blueish that looms from the water and it actually creates a nice atmosphere; but I would just prefer it not to exist at all. I am a light sleeper and any form of light generally disturbs me. That being said, I'm rather amazed that I have been falling asleep just fine every night despite having the humidifier on my nightstand. I guess the type of blue it emits would unlikely disturb sleep, however the nuisance still stands for me. The second 'con' is the lack of an integrated hygrometre. Now, given the size of this humidifier I wouldn't actually expect it to have one integrated - besides it is meant to be used for travel or office use. However, if it had one it would have just made this product better than excellent and an absolute must-have for all those suffering from dry eyes/skin.
All in all, absolutely satisfied with this humidifier and given its quality and great performance it seems like money worth spent.