Before you spend a lot of money on a constant pull stringing machine consider my recent experience at a local pro shop: I was at a local tennis shop discussing machines with an individual who has been stringing rackets for 30 years. The subject of constant pull came up, and he claims it is marketing hype. We walked over to his stringer and proceeded to string a racket. He asked me to time him on the length of time tension is being pulled on the tensioner before the string is clamped, I replied 4 seconds. He then asked, how long before the next string is positioned and ready to pull tension? I replied 14 seconds. On a constant pull machine you are pulling tension for 4 seconds, but are locked out by the clamp for 14 seconds. The clamp act as the lockout mechanism negating the benefit of the constant pull tensioner. In effect the constant pulling tensioner is disrupted by the clamps which cannot do anything but hold the string at the current tension. After reading the article at http://www.racquetsportsindustry.com/issues/200609/200609stringselector.html discussing what happens to string tension, he may be right. More tension is lost once a force is applied to the string, than worrying about 1 or 2 pounds of tension on the stringing machine. As an example, Prince synthetic gut 17 strung at 62 pounds lost 10.69 pounds after allowed to sit for 200 seconds, and then struck 5 times by an object emulating a tennis ball. Constant pull verdict is still out for me, I have owned both!