ML and S posted a Yaesu FT-991 vs FT-991A video on their channel showcasing the differences between the previous and updated models.
The main differences shown in the video are the waterfall display on the new model, along with the fact that the audio is not muted when sweeping through a band. It is also mentioned that the touch-sensitive display is more responsive to touches, instead of the previous model where you had to press harder for a touch to register.
You can also get the Yaesu FT-991A here.
Here is the video, enjoy:
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