HiDonny,
Happy new year to you too. Sorry bit late getting back, just sent off last of my Xmas guests, had 6 staying over Xmas, worn out haha.

Quite frankly if you do use audio backing tracks , biab could be worth looking at more so than VArranger, mainly because you already have an arranger keyboard anyway.

Arranger styles were better suited to the type of songs I liked, big band , Latin , show tunes.
Biab has great country, rock , pop , jazz etc, did notice it has big band now too.

I’ve had biab since day one, never really used it to it’s full extent, I enjoyed playing around with my keyboards too much. Actually if all I wanted to do was create backing tracks to sing along to, or as backing for playing another instrument, I’d be more inclined to buy biab over an arranger keyboard, provided the styles suited.