I've found that etudes written for oboe, sax, clarinet and violin are different than what we find in trumpet etude books. This difference is enough to help keep us more alert. Duets But most people also agree that it's a LOT better to sight read duets than to just read etudes. There are several advantages to reading duets. The first is that it's a lot more interesting, more fun and more entertaining than reading etudes.
Etudes are studies.
Some of them are interesting, but for the most part, they are only one step away from being exercises. Duets are usually more musical and therefore more interesting. Duets also give us a true ensemble setting. Granted, that ensemble is of only two players, but it's still an ensemble. The two parts have to coincide with each other.