the silver signatures were/are great speakers- imaging especially is superb. and, the sig-30's add some bass to that already great performance. plus, they look stunning. at $4500 they'd be a good deal. the tweeter may be a little "bright" for some tastes, IF that's an issue for you. good acoustics, a good cdp, and a good amp help to tame that problem.
except... the latest diamond b&w's are probably better, but
they don't come cheap.