The Airspy,, is now providing better results on ADS-B reception than the standard FR24 receiver.
Using this software: ADSBSpy,

My own tests: FR24: 125 aircraft around 220nmi - Airspy 140 aircraft 230nmi.
The Airspy is a clean receiver which uses no LNA.

With a LNA some user has already reported 260nmi with an antenna inside the house behind a wall on the top floor:
This is the result:

When using a preamp, the Airspy really becomes a premium ADS-B receiver.
And of course, when you're not interested in ADS-B, you have a premium wide band receiver, 24 - 1800 MHz.