A few weeks ago I was looking up some "modern" sub stats to compare to the WWII boats. The Sturgeon-class attack boats, that started construction in the early 60's, could go to a test depth of 1,300+ ft. and a top underwater speed of 30 kts (with a 11.2 Mega Watt power plant). Compare that with the improved (688i) Los Angeles boats that have a test depth of 1,600 ft+ and a 35 Mega Watt power plant. Their "leaked" underwater speed is 33+ kts, but when you extrapolate the numbers from the Sturgeon's layout (compare reactor outputs and start with Sturgeon's advertised speed), the 688i boats can do around 65 kts under water. That's hauling some serious ass. Plus, a rough crush depth calculation puts them at 2,400 ft. Pretty sobering when compared to a Tench boat.
Crew sizes are around 135 men these days and an LA boat is only 362 ft. long - compared to Batfish with 311+. The newer boats are more crowded than the older ones, because of the reactors, large prop motor(s), more electronic gizmos than ever, etc.