If you look at some of the top boats (under 40 feet) they will often have a set of B&Gs... and a Prostart. Why? The Prostarts are easy to use, wireless and battery powered, and connect easily (so I am told) to analysis programs. If you use it correctly it can improve your starts. You can also train your whole crew on how to read the "distance to line" so they know when to trim in and start hiking without you needing to tell them. The compass is very accurate. Speed is GPS speed, so it can be misleading. Somewhat helpful for wind shifts but any good tactician is writing things down as noted