I had a number of hostas which had the telltale HVX symptoms ... a total of 9 in all in 4 distinct groups. There were two groups of 3 where in each group a plant had been split ... these were Gold Standard. There were two Stained Glass ... and then a single Guacamole. All appeared to have the streaking along the veins and the mottled leaves.
Since this was my first experience with HVX, I ordered the test strips to be certain. The tests showed that all the Gold Standard and the Guacamole were HVX positive as suspected. But surprisingly both Stained Glass came out negative.
My conclusion was that while observation is of course the essential first step in detecting HVX, there is no substitution for testing to avoid being fooled.