Trafalgar and Switsure class boats... they're bigger, but not by much then ww2 boats ;-)
As for Typhoon Class boats.... they were significantly longer then Charlie class vessels iirc, and their hulls were in three parts, the pressure hull for the crew, and two smaller presurised hulls that held the reactors and propulsion systems from what I've been told.
swimming pools? only if the reactors leaked ;-) but yes the quarters were very spacious by most standards, but you have to remember that most of that space was taken up by missile silos.
oh and its present tense on their size, they *are* big subs, as they're still around rusting in the dockyards. The pholipines at one point wanted to buy one and hook it up to their mains power grid, using its reactors to supply electricity... It was recommended against for some reason.
Another interesting fact is that the worlds fastest hunter killer submarine (and possibly fastest submarine period) was the Russian Alpha Class, with a top speed just shy of 50 Knotts, and with its titanium hull, it was also one of the deepist diving combat submarines ever produced.