[MattyC]

Haven't read this whole thing, but it would seem any longtime collector knows what's up:

The 1952 Topps Mantle is "the" card. Most popular of the two. Sort of the standard bearer of the Post War card hobby to the public.

The 1951 Bowman is Mantle's rookie card.

Though beauty is entirely subjective, I'd venture many collectors would say both are appealing to the eye.

For Mantle or Post War collectors, both are big cards to own.

And both present the collector with unique challenges, in terms of finding an eye appealing specimen. The 51B has endemic centering and focus issues. The 52T has endemic centering and tilt issues.