New setup (FA New Dongle + FA Antenna) worse than old setup (Old SDR + Stock Antenna)

It is worth trying. It may solve your problem. If it does not, then add a Filter
.
.
.

If you need a filter with Pro Stick, you will need a filter with Pro Stick PLUS also.
Please see this post:

https://discussions.flightaware.com/t/flightaware-pro-stick-plus-refusing-to-outperform-cheap-dtv-dongle/25655/4