I found it impractical. The music sheets are too far (yes I could have guessed this before), which means that you cannot print them too small (for me, A5 is the best size), and when you have some of them, and perhaps you put them in a binder to keep them organized, you start to feel the weight. Also, if the binder is not rigid, it will hardly stay straight and firm, it will likely bend and move. The best way to use it for me is simply with the loose sheets and a piece of cardboard behind them, to prevent them from bending.
If you don't have problem with your sight, I'd rather go with a lyre that can be attached on the piping of the trumpet, so the weight is more balanced, and you can print smaller sheets.