In my listening experience, I would say that noise reduction is the very best thing modern radios have brought to the table, and it's the thing that matters most to everyone except intense contesting and DX pileups, where extreme selectivity and dynamic range matter too. (That, and waterfall displays, but that's not a performance metric per se.)
However, there are some really excellent outboard DSP units on the market today for use with any receiver, including those beautiful vintage receivers (for example, the DSP noise reduction units made by BHI, West Mtn, SOTA, etc).
73, Ed