The Tuner on the R-2000 is actually quite sophisticated. It will easily out perform the ones in your RX-1603, 2500 and SX-1250.
As for the "horses", bear in mind that the R-2000 is 2 generations down the road from the CR-3020 and benefited from all of the advanced research being done at the time. Most importantly, it has much geater dynamic headroom than the CR-3020, which was designed at a time before that was considered of much importance. Yamaha's spec on the R-2000 was that dynamic headroom was "3dB", effectively 300 wpc for 20ms transient peaks. Not quite a Hitachi SR-2004, but that'll get the job done!
The Owner's Manual for the CR-2020 does not list any Dynamic Headroom spec. and so I doubt that the CR-3020's does either.
As for other parameters, the R-2000's S/N Ratio in FM Stereo is listed at 81 db, the CR-2020 is only 73 db (the same as the Marantz 2500 according to the Test Report you posted) so the R-2000 is capable of producing noticeably cleaner FM Stereo than the CR-2020 or the 2500. I doubt that the CR-3020 is in the same league as the R-2000 either.
So, for all intents and purposes, R-2000 is a more powerful and better sounding Receiver than the CR-3020. It is also "faster" and "cleaner" sounding, given the electronic refinements. Bear in mind that Yamaha continued to push the "State of the Art" during this time, unlike some other companies which faltered. All the CR-3020 really has over the R-2000 is sheer physical presence.
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