Musical arrangements are par for the course. They are necessary at times to tailor music to the availability of instruments to hand and the skill of the performer. Some arrangements works particularly well whereas others are just best left alone. If there’s a piece that you’d love to play then by all means enjoy playing an arrangement that works for your chosen instrument. However, I would avoid choosing arrangements as exam pieces. Why would you choose an arrangement when there is a wealth of beautiful music written specifically for your instrument. If you only play arrangements of popular pieces then you miss out on delving into the canon of music and artistic heritage of your chosen instrument. Don’t miss out on the opportunity to really dig into the musical timeline of your instrument and the different techniques that are required for such pieces. If you only choose arrangements you get a narrow perspective in your musical development.