I've tried pretty much every shaft mentioned in this thread. I don't know why people are having such trouble answering what seemed like a pretty straightforward question. Of course there are many parameters that make a shaft "good", or "effective". Some of those parameters are about the person using it. Regarding *only* low squirt characteristics, the answers are pretty easy.
Predator 314-3 is going to be the lowest. The OB1+ is pretty close, as is the OB Classic. I would put them right in that order. This is as far as current production stuff is concerned.
For some reason, Meucci and Tiger make claims about their products being "the lowest". They are mistaken. I literally proved to the Tiger guys at their booth at the expo that my 314-2 had less deflection than their corresponding shaft. The tiger shafts have other qualities that make them very nice. They hit great and have good feel and build quality. I really don't understand why Tiger wouldn't emphasize these things, rather than make demonstrably false claims that they can't support. As for Meucci, I loved the Pro shaft. Hit very nice, played great, and was low deflection for sure. Was it as low as a 314-2, or 314-3? No. Clearly not. But it played fantastic and would be a good choice for many people based on its other qualities.
Hope this helps.
KMRUNOUT