Hi Keith,
I have arrangers now but I've also had workstations & synths.
Back in the early 90's, I didnn't think the arrangers of the day had as good a quality of sound as the synths and workstations did.
So I used to create a song in the arranger and then modify it and play it via a synth or workstation, to try and get better sound quality.
Nowadays I only have arrangers as the sound quality and features are pretty remarkable.
The reason I use an arranger rather than a workstation is that I personally don't have the musical skills and knowledge to actually build an arrangement track by track, I'm dependent on an arranger for the style parts to create a song.

best wishes
Rikki