I have had mine for a year now and it gives me around 3 days use per charge but I am a bloke and a Nothern bloke at that so I keep my words to a minimum. Great clarity when driving and it even works well outdoors in high wind.
This has saved me getting fined and makes for more pleasant car journeys.
It was easy to set up with my Nokia phone and it allows voice recognition dialling once you set this up on your handset.
Can be used on either ear and once on it is very secure. The rubber arm is a bit wide and may get in the way for some spectacle wearers, but mine are ultra thin and it is no problem for me.
I bought mine in the sale at a well known electronics store and I would buy the same again.