I already have a small world play through but I didn't want to get too deep and go into hard mode and then realize I should have started with a large world.
Large worlds may contain more than one of a biome, not counting snow and jungle but it may be preffered to use expert medium or large worlds
Large worlds will have more resources in them. Hadrmode and Pre-Hardmode resources
Small worlds on the other hand, you can travel from place to place much quicker, I usually pick medium sized worlds due to the ease of getting to places
Medium world are usually the way to go
What do you think?