Yes, I play. I don't have a Trinity College, although I've played on lots of their instruments over the years (I've taught octave mandolin classes a lot and spent a long time working in a music store that carried them). The big difference between the octave mandolin and the bouzouki is scale length. The octave mandolin is close to too short, and the bouzouki is close to too long. If I had to pick one, I'd definitely go with the octave mandolin. It is a lot easier t play and has a more solid and snappier sound. They also come with the bass courses strung with unison strings. The bouzouki comes with octave strings on the bass courses, which I think gives it a whimpy and somewhat indistinct sound. This could be changed on either instrument, of course, with a new nut and saddle.

John