I find it very boring to level my paladin compared to say, my mage, who has more interesting tools for killing mobs. But it's definitely easy to level paladin- I have a mouse button bound to alt-tab so I can just judge a mob, start autoattacking when he's in range, use the alt-tab mouse button to pull up a website I'm reading, alt-tab back to the game in 10-15 seconds or so and the mob is dead and I haven't lost much health. It's pretty close to afk leveling.