Silver/unlacquered are believed, by some, to resonate more or play more brightly. Pro or con, you decide. I'm not convinced that there's all that much of a difference as I've owned silver plated, unlacquered and lacquered horns and played them against others in the music shop. The mouthpiece I am familiar with sounded basically the same on each horn, so don't look for finishes to make worlds of difference in terms of sound. Some people have allergies to brass, so unlacquered would be a bad idea. You'd hate to find out with a bad case of contact dermatitis that you are allergic to your instrument. Silver looks amazing, but will develop fine scratches very easily - you have to be careful to retain the mirror-like finish if it's polished silver. Special care in cleaning it and keeping the dust off of it is a must. Silver also tarnishes - which can be slowed to some extent with special strips you put in the case.