Interesting critique, and consistent with estats being your first love. I actually think the Susvara's soundstaging is superb overall, but as with bass, you'll need a powerful amp to really hear its full potential there. Certainly some estats (009S and SGL Jr., e.g.) have a more precise and layered soundstage, but they aren't dramatically larger in dimension IMO. I haven't heard the SGL Sr. yet, but the Susvara has more weight than the SGL Jr., if that means bass authority. Estats will always outdo planars for
texture on the whole, just due to physics.
The beauty of the Susvara is that it may not be the absolute best in any one aspect, but it's far above average at everything, and it's all in wonderful balance. That still makes it the one headphone I'd own if I could only own one. Looking forward to auditioning the SGL Sr. and Stax X9000 to see it they can displace it.