I'm not sure quite how to assemble the various references in the books, both tacit, implied and explicit, about racial and trait differences into anything really simple. However, I would not be so sure a Ringwraith is quite the comparison to make here to the Eldar. Ringwraiths were beings imbued with Sauronic will, sorcery, evil, fortification and purpose. They had a Ring of Power bolstering and warping the underlying essence of their mortal being.
Tolkien often made specific reference in concepts ranking Elves and Men. Certain of the Eldar and Men are ranked against each other, and compared in specific ways. Those went beyond superlatives and implied, often but not always, inborn traits or capacities, though he also noted environmental impacts on the achievement of greatness, such as the Light of Aman and how it changed the Elves. Numenoreans were altered, it was sometimes implied and stated, by the Isle of Numenor's proximity to Valinor.
Amongst specific traits and concepts cited in this ranking, Feanor for example, (notwithstanding his unfortunate personality--narcissism) was described, specifically
"For Fëanor was made the mightiest in all parts of body and mind: in valour, in endurance, in beauty, in understanding, in skill, in strength and subtlety alike: of all the Children of Ilúvatar, and a bright flame was in him." ― The Silmarillion, Of the Sun and Moon and the Hiding of Valinor.
He was clearly different and distinct in other ways. His mother, Miriel spent herself, somehow during her gestation, and imbued Feanor with this greatness. She passed on and was off to the Halls of Mandos (or was it Gardens of Lorien--Valinor not Middle Earth) after birthing Feanor. His Spirit burned more hotly. His body was consumed by burning fire when he was slain in the first Great Battle (I forget its name) between the Elves and Morgoth in Beleriand during the First Age.
There were references to greatness of heroism (Beren) and those of 'fairest' form (Luthien, whose likeness it was repeatedly said in the third age, lived in Arwen), and then Galadriel, in her blended Noldorin (half-cousin to Feanor through Finarfin), Vanyar (Indis was her grandmother) and Telerin (through Earwen, of Olwe) heritage
"Very tall [Galadriel and Celeborn] were, and the Lady no less tall than the Lord; and they were grave and beautiful. They were clad wholly in white; and the hair of the Lady was of deep gold… but no sign of age was upon them, unless it were in the depths of their eyes; for these were keen as lances in the starlight, and yet profound, the wells of deep memory." ― The Lord of the Rings, "The Mirror of Galadriel"
and often referred to, also, as fairest of all the Elves, both in Aman and Middle Earth.
Greatness in Men has particular emphases in certain traits, such as with Aragorn who had the "foresight of his people" (Numenoreans, as stated several times in The Tale of Aragorn and Arwen), as did Gilraen his mother. When he was clad in raiment of, I think it was green and silver (Tale of Aragorn and Arwen), in Lothlorien, where he pledged his troth to Arwen at Caras Caladhon after, I think it was 40 years adventuring, travelling, and fighting. He first saw Arwen when he was new to manhood, around 20, in Rivendell. He was seen by Arwen, again, after his honing in the wild, and upon return, seemed as a great lord in the impression he conveyed, mighty amongst even the Eldar. We're also told this many times about particular members of The Followers, such as of Tuor in his approach to Gondolin (I dunno,

all that flowing golden hair and stuff that he had--sounds a bit liker a surfer dude to me

) and in his likeness to the Eldar, and successful courtship of even Idril Celebrindil, daughter of the then High King of the Noldor, Turgon, who was only two generations down from Finwe, High King of all the Noldor. We're also told that in the First Age, Elves and Men approached each other in stature, greatness and heroism.
Tolkien, not always, compared races on height/stature. Often he referred to presence or greatness in bearing, but also more, as he often cited light in the eyes of the Eldar (not really so of the Elves who never went to Aman). That 'light' he also attributed to Numenoreans (again whose stature was greater, though their wisdom, potency, and vigour/constitution was also greater). About vigour, an example is the Eldar who did versus did not succumb to cold during the crossing of the Heclaraxe. Resistance to sickness seemed to vary in the races and Elves did not struggle with mortal afflictions. I never heard of the Plague periods affecting Elves, though it decimated the Numenoreans in Exile, particularly in Arnor. Was it King Ondoher and, I think all seven of his children, who perished in the Plague that came out of the Morgul Vale? They were Men of the Westernesse, not your average, ole human of normal lifespan.
Implications were also drawn about capacity to resist evil. Men were more able to be influenced by the Yoke of Morgoth, who, I remember reading, could continue to influence mortals from even beyond the Doors of Night, in the Void, where he had been cast after the War of Wrath that ended the First Age. This relative vulnerability to evil, for example, by perversion through Sauronic influence was often attributed to Men (Boromir, Isildur and the Ring).
Tolkien also noted that there was something in the fibre or sinew of Hobbits more resistant--tougher--somehow in their capacity to tolerate the evil presence of Sauron through the ring. The same is implied about Sméagol and his near 900 year (or was it 400, I always forget) proximity to the Ring and failure to succumb to wraith form. Again, there is reference to this relative capacity to resist Wraith-ick transfiguration in the Dwarves who never became wraiths through possession of a Ring of Power.
There was also Ghan Buri Ghan, which is another oddity in the mythology, where, through reference to an unsullied or untainted laugh, Tolkien notes something different about this strain of human. Although not 'greatness' as Tolkien often cast it (like he never counted Ents amongst the 'great' in that particular way), Ghan Buri Ghan had something 'special' or 'greater' by way of relative ranking, than others of mortal kind.
All this leads me to conclude that there are specific ways to compare the races that have strong basis in the mythology as Tolkien cast it. Exactly how and where is difficult, exactly, to pinpoint, but comparisons and relative rankings can be drawn for different Ages, races of Men and Elves and in numerous ways.