Right now it's dimension doors...
1. Essentially a void age without all the hassle of Mystcraft page collecting.
2. Keep inventory on death
3. Normally nothing spawns in a Dimension Door Age (have seen slime and those annoying monoliths-but more on that in a second)
4. Resources like stone brick, chiseled stone, wood chests, iron bars, redstone, pistons, tnt, etc etc etc all without fear of mobs.
5. Making a soul shard spawner and not needing to worry about losing inventory on death makes for some happy fun time battling waves of zombies when bored.
6. Limbo unraveled fabric of reality is a take-no-fall-damage block and easily harvested with punching or tool.
7. Daylight cycle the same as overworld so running factorization solar steam boiler and solar panels is possible
8. No rain.
Oh wow ... so totally left out those monoliths ... I use them early game to quickly scout out around my map for stuff. When you escape limbo you randomly go up to 500 blocks away.
Yeah, I'm liking it.