I’m using an orange FA Pro dongle that I bought in August. I did pay almost double the price compared to Amazon but I’m unable to purchase directly from Amazon in my country so I had to get mine from a private reseller who adds a large markup. Everything to do with electronics, computers, cameras and photography, etc. costs more here than in the US. Prior to that I used a Nooelec NESDR SMArt dongle.
Regarding the Radarbox dongle it’s possible that you need to adjust your gain or possibly set your PPM for it. Unless you’re using PiAware/dump1090-fa version 6 or higher with adaptive gain and your dongle’s PPM is 0.5 due to its TCXO you’d need to tweak these settings by hand then restart the dump1090 service, then monitor for a while, repeat as necessary until you find the gain that works best with that dongle. If gain’s set too high you’ll receive fewer messages due to signal distortion and front-end overloading. It will appear just like a gain that’s too low as far as messages received and planes seen.
In my case I was seeing a lot worse performance with my new FA dongle vs. the NESDR SMArt until I added a 1090 filter near my antenna.
Re: differences between FA Pro Plus blue and Radarbox green you can compare the technical specs of both of them yourself. They both contain preamps (LNAs) and filters but the amps may have different amounts of amplification and the filters may be of different designs. You can probably find out by searching the web.
(Disclaimer: I only started tracking planes with ADS-B software in July 2021.)