First Lensman vs Four-Day Planet: Which Should You Read?

Cover of First Lensman First Lensman Edward E. Smith · 1950 ★★★★☆ 3.9 306 pages · ≈ 5 h 40 m · Moderate Find on Amazon
vs
Cover of Four-Day Planet Four-Day Planet H. Beam Piper · 1961 ★★★★☆ 3.8 162 pages · ≈ 3 h 00 m · Moderate Find on Amazon

The verdict

Side by side

First LensmanFour-Day PlanetEnjoymentDifficultyInfluencePopularityClassic
Space colonies -- FictionScience FictionFiction