I find it fairly easy to survive on either. Default generation is certainly much nicer but it can be cruel (ultra small beginner islands). I like to switch between both each time I play. Test is crazy. You get massive worlds sometimes pig houses and bee hives spawn in the ocean, hundreds of spider nests and yes the lack of a pig king gets annoying but the biome meshing doesn't really work well. I've found they tend be split into different islands more often than default.