I'd say it's going to be pretty dramatic. The EX500 was a nice set, but the GT50 will be leaps and bounds beyond it.
I have a full-array LED backlit Sharp LCD and the difference in image quality is pretty huge between it and my VT50.
desktop + headphone Sonus faber Toy monitor|REL T Zero|Sony UDA-1|Sony MDR-Z7|Sony MDR-1000X|Audioquest NightHawk|Ultimate Ears Triple.fi 10|Sony NW-A35
ht Sony A1E 65" OLED|Monitor Audio Silver RX6, RX Centre, RX1|SVS SB-2000|Sony STR-ZA5000ES|Sony UBP-X1000ES|Sonos Connect + Peachtree Audio DAC•iT|Panamax M-5100PM
stereo Sonus faber Toy tower|REL S/5|Teac UD-501|Sony TA-A1ES|Sony SCD-777ES|Sony ST-SA50ES|Sony 43" X800D|Sony UBP-X800|Sonos Connect|Furman Elite-15 PFi