Let me complicate matters just a bit as far as sound is concerned.

My only experience is with banjos. I cannot speak for other instruments.

A banjo has three different (sometimes extremely different) sounds. 1. What you, the player, hear. 2. What the listener hears. 3. What is heard on a recording. It is not necessarily a no brainer to pick which sound to go with.

For example, I don't like the sound of a tubaphone when I am behind the banjo, But I like the sound I get when I'm in front of it. How do I know? True story: At a festival I played a tubaphone. After some noodling I handed it back to the vendor (someone I knew) and said that I really could not get excited by the sound of the banjo. I forgot that the minidisc recorder in my pocket was on. Later when I got home and played that disc I heard me playing. I thought "Wow, nice tone." Then I heard me telling the vendor that I didn't like the tone.

It is not really a question of which sound is "right." There are a million different banjo sounds and all are JUST RIGHT. What you are looking for is the sound you want to hear (or you want the live audience to hear, or you want the listener to hear on a CD) when you play the banjo. Don't dismiss your inner instinct. Pay serious attention to it. I know more than one banjo player who bought a banjo because someone else (presumably more knowledgeable than they) liked it. The relationship didn't last. It's like marrying the guy your parents like best.

The most important thing to do is listen, listen, listen to banjo playing, live and recorded. Dwight Diller says a person learning to play banjo should spend most of his/her time listening.

One thing I've noticed is that not all banjos are equally user friendly, but some are worth some time and effort. My banjo is a Mike Ramsey Bacon. I pulled it off the wa11, strummed the strings and thought "YES!" and bought it. But the early going was not easy. There was no honeymoon. It fought me every step of the way. I learned early never to show fear in its presence. It took a while to hear the same sound in my playing that I heard the first time I strummed those strings. I have since learned that this is not an unusual experience for Bacon players.