The Test Team edition knives were an initial limited release sold at one of the Blade shows. They were similar to prototypes, and (as I recall) they were sold at a somewhat reduced price and the buyers had to agree to not sell them for six months (that period has expired, so they are free to sell them if they want to). Buyers were encouraged to provide feedback on their Test Team knives, and some of their suggestions were used to redesign the knife for a full production run.

Test Team knives are slightly different than the production run; as with anything, some people prefer the Test Team versions, either because they're less common or because they didn't like the production run changes, but those changes were made as improvements based on user feedback, so I prefer the production knives.