Some of the latest portables have features not available on older desktop receivers, such as numerous filter bandwidths, sync detection, etc. For example, the Tecsun PL-880 comes to mind.
The R-600 also was rather basic on features, even during it era. I am not kicking it, as I have one, but I am trying to be realistic with the progress of technology. I hold on to my Kenwood receivers, as they suit my casual HF listening needs. I have worked in computers for most of my professional career, so sometimes it is good to just to turn off the computers, turn on a radio, and spin the dial.
Also note the risks of buying an older desktop receiver. Capacitors can leak, resistors can drift, solder joints can break, and a myriad of other concerns. Be prepare to fix them, or have them fixed. A prime example, solder joints at the attenuator in my R-2000 needed reflowing awhile back. It is not a difficult fix - well, for my hands these days it is a challenge (another topic) - but it is annoying ongoing maintenance of aging radios nonetheless.