I have mixed experience.
I set Revo control & telemetry first, and use Bluetooth module to transmit telemetry to my laptop. Luckily I did not fly too far. There were connection loss in roughly 10 m distance. I was not a radio problem, but rather Bluetooth sort of interference or data jam. Radio signal was perfect (50 db), it was abrupt loss with no subsequent recovery.
When I tested without Bluetooth, with USB connection to computer, I got over 500 m at 25 mW power with no direct sight (walking test, through trees).
I also got very good connection and non-delayed telemetry update (test on calibration bar dynamic) when I start using RMILEC 433MHz SRC771 1/2 Wave Length UHF Antenna on TX side.
Hi mookie, are you using stock Sparky 2 helical wire antenna?