We had in inherited an old monitor from family members, and needed to find a new one because of the wear and tear after 3 kids. We shopped around and looked at other reviews. We bought the Sony 900mhz at first, but there was a lot of interference. It was hard to hear our daughter at all unless she was actively crying. We bought the imonitor and love it. The sound quality is good. The volume adjustment is very convenient. When my daughter is sick we can turn it up to attend to her more closely. We haven't had it long, but are very pleased so far.