Read the fine print as to how their gain figures are derived.
Comet, Diamond and the other imports DO work; not one said they didn't. Light bulbs work as antennas, too.
I'll put a comparable Larsen against any of the imports any day. The Larsens are better made, last longer and have honest specs. Ask any of the commercial shops and see how many of the imports they mess with.
Been installing radios and antennas in vehicles for about 40 years now - amateur commercial and a lot of stuff in between.
Lon - W3LK