I had a galaxy and got rid as soon as possible.
Friend also wants to do the same.
It has a few glitches in the OS that frustrated me although doesn't necessarily stop it working.
Also after about three months both myself and my friend experienced significant slowing down of the phone.
The S3 feels a bit cheap with the plastic back cover.
the HTC One I have no experience of but it looks like a fantastic phone.
Although, given the choice I'd be getting the Blackberry Q10 now and hoping it's good enough
