[LoBlo]

I'ld like to see some actual sources and/or technical discussion supporting those proposed speeds.

All the sources I've read suggest that the Akula's speed currently is the one that's over estimated. A 35 knots top speed for the Akula are usually amongst the high end of speed estimates that I've come across with the low end estimates at 28 knots submerged. Also considering the fact that its displacement is estimated in the 10kton to 12kton range and its hydrodynamic shaping deviates more from the ideal with an oval rather than spherical cross section and its placement of its sail structure in closer proximetry to the aft tapering of the hull (increasing the drag effect of the sail for reasons beyond the scope of the discussion).

Overall I think 35 knots for the Akula is actually a bit generous, but anyhow there's no real point of fiddling speeds that are purely guestimates with other speeds that are also purely guestimates, might as well leave as is unless their's some unusually convincing source that supporting something else. However, if a speed is to be toned down seems like the Akula's top speed would be the more logical choice to modify.