The advantages are that they stay in tune really well and allow you to raise the pitch as well as lower it. The disadvantages are that to use alternate tunings or to change string gauges, you must adjust the spring tension, which can be frustrating if you are not used to doing it. However, The alternate tuning issue can be overcome by placing a shim (I use broken clothes pins) in the rear access panel of your guitar between the tremolo and the body. Hope this answers your question.
