My personal preference for a perfect transformation VF-0 toy would be 1/60 scale. That would already be big enough, close to the 1/48 VF-1 in size. So, my vote is for 1/60.
I think 1/48 would just be too huge. I'm already limited in the amount of display space I have and a 1/48 VF-0 in fighter mode, would probably take up nearly a whole shelf in my display cabinet. Of course, I'd still buy it in a heartbeat if Yamato made it.
By the way, don't take any of the above as confirmation that a larger scale perfect transformation VF-0 is actually in the works. I'm just stating what I would like only.
Graham