I find that all brands of pressureless balls play better than pressurized once the temperature falls below the 50s (fahrenheit). For actually playing tennis, the best pressureless ball is Tretorn. But for banging serves and ground strokes against a concrete wall, other brands are better. On hard shots against the wall, Tretorns tend to crack, spewing a puff of white crap into the air. Then you get another puff every time they hit the wall until they've soon lost their bounce.