dear friend,

Pro Arrangers are a different beast compared to synth workstations. Your equation is not really correct in all regards.

Just to help: if you use your keaboard to play live (ie. u don't use complex programming, sequencing, phrases and loops a lot), and mainly play the "voices" (sounds), then a pro arranger can do this as well as your synths do. I'd venture to say that some new arrangers (T2 for example) have even better sounds that some synths, and definetly include the vast majority of those functions (split mode that you mentioned).

On top of this, Arrangers do much more than simply play sounds, are more user friendly in sequencing and programming, and as you said, are fun to play. In most cases, they result inspiring to the player.

I personally owned quite a few synths in the past (Roland D50, Ydx7, SY77, Korg 01Wfd, EMU modules, etc), then got rid of most of them and went for a simpler solution: arranger+piano+pc.

The final answer is up to what you need/like, and the money you can spend. Most of us on this forum find that a good arranger, with the help of a digital piano and a PC, can provide an excellent pro equipment in most circumstances.

Good luck

Amelio