Shortround6
Major General
The R-2000 was a transport engine. By the time it showed up P & W was pushing the R-2800 as a combat engine.
The R-2000 pretty much offered what you would expect from it. Around 9-10% more power at similar heights compared to the R-1830 except is was skewed a bit to low altitude work.
The early R-2000s offered 1350hp for take-off, latter ones offered 1450hp for take-off. Very late (1944) R-1830s offered 1350hp (needed new cylinders).
An R-2000 could offer 1000hp max continuous at 14,000ft in high gear while an R-1830 offered 1000hp max continuous at 12,500ft. There were a number of versions.
P & W never did more than put a two speed supercharger on it and a lot of the engines used a single speed supercharger, Since just about all of them went into DC-4s/C-54s and variations with different designations (marines had their own designations) and since the airframe was not pressurized a lot of them never flew high enough to use the 2nd speed.
Some things trickled down from the R-2800.