I think that with so many possible influences - location, antenna, obstructions, aircraft attitude relative to the antenna etc - judging performance by the specification alone is going to be somewhat pointless. After all, it is the manufacturer that publishes the figures in the first place. Also, is this a minimum figure or an average to be expected if 100 boxes were to be tested? If you read the "other" forum, then you will see that users really wanted the new version to be better than the last one, but other than a general feeling that it was better, nothing was really proved.
When I compare the performance of my RadarBox, I see a noticeable difference during high and low pressure periods. Of course, even this might be a coincidence as the low pressure days might just have been low traffic intensity days and everybody may have been flying when the pressure was high - who knows :-)