Thanks for your insight, Bill. It's good to hear from someone actually 'walking the walk' on this issue, even if there are points I still find troubling...

It's in the qualifiers you use that leave me with the most doubt. And, while I know only too well that the ENGINES of most modern VSTi's are better optimized for live play, that doesn't mean that the samples themselves, and their balances especially, are, at least as far as what we expect from an arranger. Even you qualify that, and even add that some arrangers themselves leave you wanting (I agree here, the fluid seamless transitions of the old Sound Canvas days are long gone), so I would only ask you, is there ONE VSTi complete soundset (we won't even TOUCH the issue of what you do when you use multiple soundsets from multiple sources) that covers ALL the bases, that you could use as the single engine of an entire soft arranger that is as well balanced as a Tyros or Roland? To be able to switch, on a whim, from any sax sound to ANY clarinet sound and not have to move a fader, change your touch, or anything?
And yes, I understand that you CAN preset volume offsets, etc., but on a soundset with THOUSANDS of sounds, who really wants to do that, when the manufacturer really ought to have already done it? And, of course, we haven't even touched the issue of EQ and velocity curves, etc.. There's a reason I choose to work with arrangers live, even in live bands. That convenience of calling
any sound up, and knowing you aren't going to have to grab the volume knob after you have scared some customer silly! So....
"Will they be as balanced as hardware arrangers? Yes and No" still sounds a lot more like a no than a yes... unless you do all the work.
And unfortunately, I guess, I am not really looking for the satisfaction of knowing it is all you when you play a style. All I'm really concerned about is whether THEY are satisfied, and whether that satisfaction costs me a week of effort, or a few minutes. Currently, they are pretty good with how things are. Could they be better? Of course. Am I willing to multiply the effort probably 100X to get that bit better? Probably not...
My audience would be hard pressed to tell the difference, live, and when in the studio, the arranger isn't really the tool I use for original work (although I'll use the sounds if appropriate), and the issues with sound balances don't apply, and I am as willing to use VSTi's as any other sound source. But live, improvisational arranger play puts tougher stresses on a soundset than any other form of playing, IMO. The day that creators of soundsets as expensive as Goliath etc. realize that sonic balance is as important as anything else (more, IMO), they hardly qualify as sound SETS, more just sound collections. Oh, and BTW, we haven't even TOUCHED the more complicated issue of drumset equivalency.
As with any issue that I disagree with others on, I am only TOO interested in hearing examples that disprove me. I would be fascinated to hear a style, for instance, being changed live from a rock set to a brush set, and hear how well it remains balanced. I'd also like to hear styles that you have converted to run entirely on VSTi's, or those you have created yourself from scratch using only VSTi's...
Sadly, 'trying before you buy' with a Wersi is an option very few ever get the chance to do, and even fewer on an instrument that has been 'tweaked' for full VSTi use. So hearing others' work is about all we can do.
The thing that puzzles me the most is, if a soft arranger CAN be made to be as good, no, FAR better than a closed one by the simple addition of a good VSTi and a bit of work balancing the sounds, why on EARTH doesn't the factory (with the personnel already trained to do such work) do the work, and convert the styles for it? Especially for Wersi's, the addition of a $500 VSTi is hardly going to put off anyone already prepared to pony up $8k+...
Or is the work a LOT harder than you make out? Something is missing from the picture.