You really cannot tell anything about sound quality from test numbers. In fact, test numbers can be misleading. For example. if you test two tubes of the same type and one has a higher transconductance than the other, it is assumed that tube will have more gain. But only if the plate resistances are the same, otherwise the tube with the higher gain will be the one with the highest combined Gm and plate resistance.
To further complicate things, if two different tube tester are used... do they both have the same voltage parameters for plate, screen and grid to cathode? Your best bet is to purchase tubes from reliable sellers such as Vintage Tube Services or Upscale audio where they test their stock against each other with the same testing equipment. This way you can compare tube readings among the tubes they sell. Getting different readings from different sellers -- especially eBay -- is futile IMO.