There is definitely a navigational impediment if you're playing spontaneosly. There are some who say it is just a matter of getting used to it. Even so, it has to be more cumbersome to perform quick changes that are not anticipated. If you are in a studio, or a band with established sets, it is far easier, and, perhaps, advantageous. I doubt it can be argued that VST's, potentially, produce a better replication of an instrument. The problem with me is that I can't seem to match the articulations found on an arranger, unless I use programs like B4II, that has done it for me.
I have 2 GB's in the Receptor, that is 95% available for VST's. There is a vast potential for anyone experienced in software to make great music, but I don't know if I ever will feel comfortable enough in a OMB situation to leave my G-70, or even KN7000 home.
My ignorance is simply that, because there are many solo players using VST's, and wouldn't ever use an arranger. Different strokes ?
pa4X 76 ,SX900, Audya 76,Yamaha S970 , vArranger, Hammond SK1, Ketron SD40, Centerpoint Space Station, Bose compact