I have found that the better my scope, the better I hear. I use a Littman Cardiology II and more recently a Master Cardiology. They're expensive, but I won't use a cheap scope on patients that I am responsible for, unless it's the last resort. I have also never had my scope stolen nor have I ever lost one. People do lose them, but mostly because of their own fault.
I like my Cardiology II on most calls, but on calls with serious cardiac issues, I usually listen with my Master Cardiology. I can hear heart tones and murmurs (if they're present) much more clearly. On most calls however, the MC picks up a lot of surrounding noise.
Trust me...you'll notice the difference the first time you use a good scope.