To clarify the difference in crew member size between the 2 boats is 50, which is not a 50% difference but around 35 %. And whatever space that is taken up by the additional support systems I am sure the Virginia class has it covered and refined in the 4 different improvements of the design ending with the Blok IV. And this is not account the predeceasing Seawolf from which the Virginia has surely obtained crucial lessons from .My point was more about how much internal space it frees up - everything driven by the number of crew members ends up half the size which will add up rather quickly. I'd say it easily compensates for a few torpedo tubes and a couple of weapons storage racks.
The escape chamber is located outside the hull (in the sail) so doesn't compete with silencing measures for space. In the USN, evacuation is by DSRV crew transfer or free ascent with escape suit (both of which are available on Russian boats too, the preference for escape chambers may come from an expectation of typically operating at greater depth).