Any opinions on Welch Allyn Professional Stethoscopes?

I realize from lurking that the "what's the best stethoscope for students" has been covered fairly thoroughly. In fact, people get extremely passionate about their steths . Hopefully this post isn't too redundant...

I am in my fourth week as a nursing student. I am still practicing taking vitals and whatnot. A friend of mine gave me a Welch Allyn (Tycos) Professional model steth to use in school. I used it a few times, but at first found it overly sensitive. Every bump of the lumen, every finger press on the bell made a loud rustling noise. I couldn't hear the brachial pulse during BP's.

I though it was possibly the fault of the steth, so I (foolishly) bought a Littman Classic SE II b/c it was so highly regarded by students and instructors (and people online swear by them).

Frankly, I can't tell much of a difference. The Littmann may be slighlty louder through a shirt while listening to apical pulses, but that's about it. I also find that the "2-in-1" diaphragm doesn't seem to work that well for me. I guess I was expecting to be blown away by the Littmann, and it seems to be on par with the Welch Allyn. And after working more with the WA, it seems to be clearer sounding to me (though still very prone to artifact noises, more so than the Littman).

Is there any big difference between the two? Is one more sturdy, or more sensitive? Is this all just a matter of lacking practice with ascultation? And is that double diaphragm all its cracked up to be? Does anybody have expereince with the WA Pro model? Are there any other brands that you would recommend for a noob student?

Basically, which should I chose? I didn't really see a point this early in the game keeping both...