The idea here is to eliminate outside noise so you can hear the subtle sounds you MD makes. Some lower end machines just make a single beep with little variation on the sounds (no idea what the Tesoro does) So if it is a single beep no difference in sound between a pull tab and a coin, the advantages are not to draw attention to yourself and not to drive others around you nuts..
Otherwise yes they make a big difference if you use the subtle differences in sound to decide to dig or not.. Comfort is also a big deal to me.. I use in-ear phones that seal 36db or outside noise, basically Christmas tree type ear plugs with sound drivers in the middle.. Hope that helps.