From distant memory too, I would have said that the main difference between the two is that R7 Soft is bouncier and with a bit of a lower throw, in part due to that characteristic. I think Ventus Spin is very good in terms of control as far as soft tensors go, so long as you can read incoming spin to a reasonable extent (I know, that's one of your asking points). R7S may help with that in a way as, if I remember well, VS's topsheet (the old transparent type, but without some of the crazy sponges from the same generation) is softer and gets engaged very easily so that you get both very easy spin of your own and, well, more sensitivity to the one that's incoming. But at least you don't have to worry as much about the ball jumping off with the Ventus, in terms of distance. For 100% close-to-the-table play and what you seem to be asking for, it'd probably be my pick. The Rakza is more powerful and handier far from the table, not to mention a meaner trajectory - but that's not on your list.