How close is it on scale of one to ten?
Well I'd say both are 9-9.5 on performance (slickness, cushion, etc). The Maca Root probably lathers more traditionally (but both lather superbly to me) and the Bio might be a tad more moisturizing. I'd say the thing that really separates them is the scent. I find both fine, but nothing outstanding. I am aware some do not like the scent of the Maca Root at all.
About the lathering: It seems some expect all lather to look similar. I try to approach each product on its own terms. Both of these are fantastic, as far as I'm concerned. As always YMMV.