When comparing GregTech vs Biomes O'Plenty, the Slant community recommends GregTech for most people. In the question“What are the best Minecraft mods?” GregTech is ranked 2nd while Biomes O'Plenty is ranked 3rd. The most important reason people chose GregTech is:
The GregTech mod adds a huge amount of content and machine progression to Minecraft. Starting with Bronzen Steam-powered Machinery, players work themselves up to more and more high-tech technology.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Greatly expands Minecraft
The GregTech mod adds a huge amount of content and machine progression to Minecraft. Starting with Bronzen Steam-powered Machinery, players work themselves up to more and more high-tech technology.
Pro New ore generation
GregTech changes up the ore generation so that ores, both vanilla and the plethora of new ones, spawn in major veins rather than random small deposits. While finding these isn't as easy as with vanilla nodes, they make gathering the vast quantities of raw materials GregTech industrialisation needs, much more viable.
Pro Makes the world of Minecraft more diverse
Biomes O'Plenty adds an extra 75 biomes, which vary from coral reefs to massive jungles.
Cons
Con Hard balance
While tweaks can be made through the configs files, Gregtech (with many of the changes it makes) is notoriously hard, and advancing through it takes a lot longer than through other mods.