Tried one of these in a feeder that is connected to an external antenna, range has significantly increased, the range map on all metrics is visibly improved, statistics from FR24 and FlightAware show an extra 20-30% activity throughout the day.
Bought a second for a smaller remote unit and that has seen a significant increase in range.
I was surprised to also note that this is across all altitude bands, I was expecting improved high altitude coverage but the sub 10,000 foot coverage is also significant, especially with the CAP1391 ADSB in the UK.