Chuck has asked a legitimate question and deserves a legit answer. Here's my two cents worth:
I would say that playing an arranger keyboard takes a lot of adjustment if one is not used to playing chords (or quasi-chords) on the left hand. An arranger in full play mode requires one to change chords and not necessarily worry about bass lines, as the arrangement will supply its own bass. Now, it is possible to disable some or all or the left hand accompaniment and use the left hand for finger bass or comping chords. Many of our resident SZ members play their own left hand parts (Fran Carango, Donny Pesce and Uncle Dave to name a few). I'm thinking they would tell you that playing your own left hand arrangements is certainly possible and recommended. In that case, the arranger section becomes a virtual drum machine with some pretty neat patterns and fills. It will take some adjustment, but it works. The only thing that won't work, I think, is trying to play a full sound arrangement and left hand bass on the same keyboard at the same time.
As far as the feel of the Casio is concerned, that is somewhat a personal choice. I have read that many SZers love the Casio, but I feel that Roland, Yamaha and Korg are superior. You must have bought the Casio from somewhere. Do they have other brands of keyboards you could try? Keep in mind that the less expensive boards tend to have a less expensive feel along with less features and capabilities. Roland and Yamaha have some pretty decent boards in their mid-lower range.
My suggestion would be to get a hold of a good music catalog (Sweetwater, Musicians Friend, AMS) and a couple copies of music mags such as Keyboard and Electronic Musician. Read up on some of the boards and decide what your budget can afford, keeping in mind that more $$ often translates into more features and capabilities.
Lastly, your keyboard/drum machine set-up is something many of us have used before turning to arrangers. The arranger can add a lot to your sound if you are willing to use it. Maybe you would like to consider an arranger module and midi it to your Alesis; then break the Alesis into 3 zones - right, arranger and bass. Send the arranger signal to your arranger and change chords as needed (mute the bass sound)while keeping a section open for that left hand bass you desire.
I hope this helps
[This message has been edited by cassp (edited 08-22-2006).]