Yes, in my experience, the Yamaha is the closest feeling to a double bass apart from Mo's brilliant invention.
I have an Eminence for sale which, I believe, is the closest sound-wise. It feels slightly more vertical than a real upright but the lack of knee contact is not a problem as the bar on the bottom of the end pin prevents any rotation. You get used to it quickly and it feels like a real acoustic instrument with proper (if slightly light) attack, worlds away from anything with a solid body.
Contact me if you are interested. I will be posting an advert shortly. I am in Bedfordshire.
