My last band was in late 70's. I was using an organ, kicking bass pedals, and it had a pretty primitive drum section in it. After a few upgrades I ended up with a huge Yamaha FS500 organ--heavy, expense, etc. I had leslies, p.a., bench--the gear took up an entire van.
When arrangers were first introduced, I switched! I had most all of the early Yamaha arrangers, starting with PSR 50! I midied them to a drum machine, and used a DX7 for lead sounds, along with a piano module.
As arrangers progressed I had just about all of them, Technics, Yamaha, Roland, Ketron and finally Korg. I've probably had 30 different ones at least!
The Technics 2000 was the first arranger with which I could eliminate the external drum machine, and it also had some pretty good lead sounds, so gradually stopped using all the external things.
The first arranger I had with an internal vocal harmonizer was Yamaha PSR8000. It was really way ahead of its time, and I used it for several years.
Later had just about all the PSRs and Tyros line. Briefly went back to modules, with Ketron Midjay and then Roland BK7m, but I much prefer the all-in-one convenience of modern top of the line arrangers! The Ketron Audya was really good, but as I got older it got heavier!

The PA4X is the culmination of a LONG journey. It way well be my last one, but I've said that many times over the years, as they just keep getting better and better. Not too many years left in this old body now though and I'm paying the price for being a "jock" when I was young. I'll be 74 in July, and the phone will probably stop ringing pretty soon.
DonM
www.donmasonmusic.com