Sorry guys, but until someone makes a computer based system that is as dependable, bombproof, easy to operate as a hardware arranger and does it for no more than a current TOTL (or MOTL) arranger costs, you can't sit around moaning...
My arranger gives me 128 notes. No matter WHAT else it is doing. No matter whether it is loading a style or playing a sequence. No matter WHAT effects routing and type they are. No matter whether it has the B3 engine engaged in or not.
It came loaded with hundreds of gig ready styles, OOTB. It came with a mature OS that doesn't crash. EVER...
Look, you want an arranger that is computer based? Stop whining, and buy an MS, or a Wersi. One costs a fortune, but works adequately (if you can get past the dated sound of most of its' ROM sounds and styles) and the other is cheaper, but an uphill battle to get working well, reliably, and you have to do most of the style development yourself.
But, these things come with problems. We have already heard what a nightmare it has become for users to change out motherboards (the very feature you are asking for) on MS's, as the core OS has to be re-written and debugged every time you do this. Where is the profit for the manufacturer to do this, if YOU change out the hardware yourself? He doesn't even get a piece of that pie, and now he has to completely troubleshoot a new OS so that you can slap a new piece of hardware in
Sure, it would be GREAT for us if they made it all software and PC based. But try to think of where the MONEY for the manufacturer to keep doing this is going to come from... Piracy will chew up his profits, and he faces a never ending cycle of OS debugging, just so you can change out the innards with cheap replacement parts...
I don't imagine anyone could stay in business for long like that, not to mention, what happens to the reliability of your arranger while the new hardware is being debugged (for free, apparently!)? Software OS's for computers need to ship in the tens of MILLIONS before the continual evolution of the software to account for new MoBo's and peripherals is cost effective. Arrangers ship in the few THOUSANDS... there simply isn't the money in it that the cost of continual OS development would not dominate the bottom line.
The fact is, on any closed arranger, there is a RISC chip that handles all the voice generation. Probably another one for effects. Probably another one for I/O. Another one for harmony generation (if your arranger has it). Move to a computer system, and ONE CPU has to do all of that, AND run the OS, and do it all without a hiccup. The Wersi is a hybrid system, with some of the sound generation and OS done in older RISC chips, and the OAS being taken care of by the computer. And it costs a fortune.
The MS tries to do it all on the CPU, and suffers from the continual development and hardware cycles that happen in the computer world faster than the arranger world can cope with. And it pays the price with erratic behavior and an underdeveloped sound and style section.
In the meantime, my G70 ticks on, sounding good enough for me and my audiences, and if I absolutely HAVE to have some VSTi's for the studio, or even stage, I can carry a laptop, and get them from a piece of hardware that the manufacturers can AFFORD to continually upgrade and develop for....