I had the HCB-120 since it first came out, and have just replaced it with HCB-150.
The battery life is amazingly long, I have charged it once in a month!
The HCB-150 is so much bigger compared to the HCB-120 that I cannot use it on my visor with it down! So if its sunny i have to put it on the passenger visor. (BMW E46)
One other downside compared to the HCB-120 is the display doesn't stay light up, so most of the time I forget to turn it off at night, but the display is brighter when on.
I dont have any problems connecting my sons SE phones, my Nokia and iPhone. I have access to the phonebooks from the menu on the HCB-150. It is quite funny listening to it pronounce the names in the phone book - has the kids laughing each time! ie Cian pronounced Cyan and Tracy is pronounced Tra-see!
I cant believe how cheap these are now compared to when they first came out! Grab a bargain!