The competing model by Samsung is the Crystal UHD TV TU7000 which comes in a few more sizes ranging from 43 to 75 inches. It is also supposed to be the entry-level of the 2020 lineup, but in terms of image quality the TU7000 is a little weaker because its contrast ratio and peak brightness are below those of the X750H. That is why it delivers an even worse image in bright surroundings. Against the X750H it also has no wide color gamut and is therefore not suitable for any HDR content. Both are missing a local dimming feature which the two manufacturers only use for higher ranking models and both have a problem with watching from side angles because the VA panel only delivers a washed out image then.
But those who in terms of sound prefer HDMI eARC and Dolby Atmos instead of DTS, should rather go for the Samsung TU7000.
The Sony X800H Bravia is the above model to the X750H and therefore its “big sister”. Against the X750H it has an IPS panel (except in the two biggest sizes 75” and 85”) which has the consequence that its viewing angle is much bigger but its contrast ratio and black level are worse. In combination with its higher peak brightness the X800H is therefore the better choice for HDR content as well as for bright rooms, i.e. watching TV in the afternoon. In terms of gaming it offers an analogue input and the Auto Low Latency Mode but still no HDMI 2.1.