To some degree, his guitar works also pay homage to Chopin, whose piano etudes were clearly the model for Villa-Lobos's estudos for guitar. These are true concert etudes for the guitar and, like the Chopin works, are meant for the stage; they are not limited to the status of mere pedagogical tools. Villa-Lobos's Estudos also represent an attempt, consciously or subconsiously, to legitimate the guitar as a concert instrument and raise it to the level of the piano... [p. 189]The Serbian pianist Julija Bal has arranged a number of the etudes for piano, and I think they sound really well on the instrument. You can listen to them at Bal's excellent website.
By the way, Jose Vieira Brandao adapted the five guitar preludes for piano. Sonia Rubinsky plays them on volume 7 of her complete Naxos series of Villa-Lobos piano music.