Needs a good wash after use or can get a bit slimy
Ease of use
Security / Hygiene
Quality / Performance
We have been using this for a couple of years now and I wouldn't be without it. It is so simple (you just tap it and it turns on and then gives a reading) but gives a lot of piece of mind that the water is the correct temperature. It floats around the bath (so you can monitor the temperature easily) and my children think it is another of their toys.