Hey tarheel,
To help clarify, there is a difference in the industry between a "tester" and "staff".
A true "tester" is a bowler usually chosen by the person in charge of the company or in R&D. It can come from the President or maybe even the engineer who wants actual feedback of a piece before it hits production. Most true test balls do not have labels (may be numbered or lettered for identification) and may not even necessarily be the same color of the ball when it is decided that it will hit production. I used to be a quasi (I say quasi because I don't know how relevant my feedback was, they wouldn't tell us) tester for Columbia where our balls came lettered only so we didn't know what they were and then we had two weeks to submit a written review back to Columbia and how they compared to other releases in the line. I also had a pro shop owner friend back in Chicago who tested for Faball and he had the only red Nail I ever saw (Nails came out Blue when produced for the consumer).
A "staff" member is a bowler usually chosen again by the person in charge of a company (because it comes out of his budget). Staff is usually chosen around the premise of sales whether you be a highly skilled bowler, pro shop owner or possess another function that would make you an asset to the company. There are also various levels of "staff", pro staff, regional staff, amateur, advisory, etc.
Typical staff contracts are yearly and depending upon the wording or legal agreement, you would be obligated to use that particular company's equipment (Storm/Roto may be different as I see pros switching at times, I may be wrong). The agreement I remember with Columbia was that I could throw other equipment during competition but could not divulge any information to competitors.
I would "assume" though that you were referring to Visionary to which the guys have already answered. Hope this helps some...
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Rick Leong - Ten Pins Pro Shop
Tag Team Coaching - Co-Founder
"El" Presidente of the Legion