I recently bought one for my mother but didn't disconnect the land line yet until we saw if the Jitterbug worked well. She can hear me fine with we talk (I have an iPhone) -- but the quality of her replies to me is absolutely horrible. The sound is distorted, it sounds like she's in the bottom of a well, and most of the time the words are not clear enough to understand. It is not her articulation that is the problem. On her landline or portable phones, I have no difficulty whatsoever understanding her.
I was very disappointed in that particular feature. Everything else on the phone is fine. I may keep service for another month and then cancel it to try another kind of phone. I hate to do that as I like the 5-Star feature -- but a basically one-sided conversation is pretty useless to me.