The complaints I recieve from almost all of my callers is that I sound "muffled", "far away", and or "digitally".. I think it's the mic samsung uses. The gain is not that good. Same for the earpiece speaker.. Even on the highest volume I have trouble hearing people.. As for the speakerphone, it makes a grille type rattle on the highest volume.. My IPhone was way clearer and louder all around. Although, some will say their calls are clear and they have no issues.. I'm on my second Infuse and it's just as bad as my first.
I am waiting for the HTC Holiday to come out. If it ends up on at&t I am going to give it a try.