I've been using BIAB since its early DOS days and bought every version since then. I use it for songwriting. I also collected all the TOTL arrangers with the intention to use them for songwriting, but have never found them as productive as BIAB for songwriting. The Korg PA5x, with its dual players and chord sequence function, is the first arranger that lets me work like I do in BIAB. Play in the chords into a PA5x chord sequence (vs typing them in in BIAB), try different styles to find the right one, mix and match parts of styles using the dual players (as shown in the Qui Robinez video), and then generate the tracks in the PA5X. I can do the same thing on BIAB using its real audio tracks and have the best of BIAB audio and Korg midi to mix and match in my DAW. I'm just getting started with the PA5x, but BIAB and PA5x make a great combination.