Some pros like the Titleist ProV1 golf ball for many reasons, the most important being that it was designed specifically with the pro in mind. It is the golf ball of choice for such pros as Mike Weir, Fred Funk, and David Toms.
This ball is described by the manufacturer as a soft ball with a l.550” diameter core formulation. Other features include a speed-enhancing, spin controlling ionomer casing, with an 0.30” urethane cover, plus 392-count dimple coverage in an icosahedral or 20-faced design. The pros on the PGA circuit put tremendous energy into their explosive shots on tee and fairway for days at a time and need a ball like this to meet their standards.
Golf balls designed for the pros, such as the Titleist Pro V1, which has a soft, thin cover and costs about $60 for a dozen balls. Contrast that price with what you would be paying for a lesser ball, but one that could certainly be a good ball for your game, such as the Srixon Hi-Spin, priced about $15 a dozen, or the MaxFli A3, at about $25 a dozen.
If you'd like to know what the pros look for in a golf ball, keep in mind that the characteristics of all golf balls are strictly governed by the rules laid down by the U.S. Golf Association. It is these rules that determine maximum initial velocity, total distance, and all the other features advertised by manufacturers.