I tried the Littmann´s digital stethoscope once, and noticed that not only it amplified the heart sounds, but also all sounds -- including the environment's. That made the auscultation quite noisy and unclear. Regardless of the brand of digital stethoscope u buy, I recommend you try them first to make sure you like it.
P.S.: I ended up buying a Littmann Master Cardiology instead and love it.
I totally agree with the above. The digital stethoscopes amplify all the sounds and not just the heart. It is actually very difficult to concentrate only on the heart sounds. I have the Littmann Carddiology III and its excellent.