As a horn player and recording engineer it is really hard to find mics that will give you enough gain without feedback to mic a horn soloist or section.  The Shure Beta 57a gives you a great marriage of high quality and good price.  I use this mic a lot in the studio to record horns since it gives you an excellent punch with a lot of bright nice colors.  I have used other mics like the SM 57 or the Sennheiser MD421Mk2, but the Beta 57a blows them out of the water.  It works great for saxes and clarinets since they both need a more broad pick up of sound.  I would highly recommend this mic to anyone who likes the SM57 sound, but is tired of the low sensitivity.  The extra $60 bucks you pay over the SM57 is well worth it.