First Hero and City Enchantments
After playing LH for a while I find that the spellbook that the first hero has makes an inordinate impact on the game.
I like the way heroes are recruited now, and I like the way city enchantments are powerful. But early on (before turn 10) getting a hero with a favourable spellbook that your sovereign does not have (earth mainly, but also life for kingdom, or water for epic games especially) makes a very large difference in the difficulty/speed of a game.
