I was rather apprehensive about purchasing the Pro Stick, Filter and Antenna and I imagine you might be as well. This is a real world example of the performance.
Location – Johannesburg South Africa near Rand Airport & O.R Thambo International
Hardware – Raspberry PI B (Original 512MB). Traffic is fairly low in RSA so the CPU is fine at regular clocks
Installation – Single Story Chimney ±6metres with mostly clear sky on horizon only light trees (10 metre cable)
This was an upgrade from an RTL TV Tuner with a DIY Antenna, the DIY Antenna got a typical range of 100-150 miles. In some directions the distance was further but this accounts for typical range which was fairly reasonable for a cheap solution running less than $20. While I did not expect to get 10 times the performance out of the Pro Stick I was hoping to get near the theoretical maximums and at the very least 200+ miles. In simple human terms I would expect to see roughly 500km ground level vs the sub 300km I achieved on a DIY antenna.
As you can the results are not bad at all and if you keep in mind that these results are at the limit for the location of the antenna there is little to complain about. It is possible that slightly better range could be achieved by increasing the height of the antenna but it would likely not improve much.
There are some other improvements as well, the message rate has tripled and the accuracy is slightly improved on MLAT. The filter may be a big contributing factor in this regard since my previous DIY solution had no filter. In short if you are considering a proper ADS-B antenna over a DIY antenna you can rest assured that there will be improvement although you will need to decide for yourself if it is worth the large price jump over a DIY solution.