I'm not familiar with "suri waza," could you post a link showing what you mean? I'm familiar with suri ashi
(a kind of foot work) and suri age
(a kind of sword work), but I'm not sure how that relates yet.
Ah...I see now, suwari waza. My "understanding" is that suwari waza is good for getting us to "sit within our base;" to move from the hips and trunk...for whatever it's worth.